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
  25 #include <net/pkt_cls.h>
  26 #include <net/ip.h>
  27 #include <net/route.h>
  28 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  29 #include <net/netfilter/nf_conntrack.h>
  30 #endif
  31
  32 struct flow_head {
  33         struct list_head        filters;
  34 };
  35
  36 struct flow_filter {
  37         struct list_head        list;
  38         struct tcf_exts         exts;
  39         struct tcf_ematch_tree  ematches;
  40         struct timer_list       perturb_timer;
  41         u32                     perturb_period;
  42         u32                     handle;
  43
  44         u32                     nkeys;
  45         u32                     keymask;
  46         u32                     mode;
  47         u32                     mask;
  48         u32                     xor;
  49         u32                     rshift;
  50         u32                     addend;
  51         u32                     divisor;
  52         u32                     baseclass;
  53         u32                     hashrnd;
  54 };
  55
  56 static const struct tcf_ext_map flow_ext_map = {
  57         .action = TCA_FLOW_ACT,
  58         .police = TCA_FLOW_POLICE,
  59 };
  60
  61 static inline u32 addr_fold(void *addr)
  62 {
  63         unsigned long a = (unsigned long)addr;
  64
  65         return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
  66 }
  67
  68 static u32 flow_get_src(const struct sk_buff *skb, int nhoff)
  69 {
  70         __be32 *data = NULL, hdata;
  71
  72         switch (skb->protocol) {
  73         case htons(ETH_P_IP):
  74                 data = skb_header_pointer(skb,
  75                                           nhoff + offsetof(struct iphdr,
  76                                                            saddr),
  77                                           4, &hdata);
  78                 break;
  79         case htons(ETH_P_IPV6):
  80                 data = skb_header_pointer(skb,
  81                                          nhoff + offsetof(struct ipv6hdr,
  82                                                           saddr.s6_addr32[3]),
  83                                          4, &hdata);
  84                 break;
  85         }
  86
  87         if (data)
  88                 return ntohl(*data);
  89         return addr_fold(skb->sk);
  90 }
  91
  92 static u32 flow_get_dst(const struct sk_buff *skb, int nhoff)
  93 {
  94         __be32 *data = NULL, hdata;
  95
  96         switch (skb->protocol) {
  97         case htons(ETH_P_IP):
  98                 data = skb_header_pointer(skb,
  99                                           nhoff + offsetof(struct iphdr,
 100                                                            daddr),
 101                                           4, &hdata);
 102                 break;
 103         case htons(ETH_P_IPV6):
 104                 data = skb_header_pointer(skb,
 105                                          nhoff + offsetof(struct ipv6hdr,
 106                                                           daddr.s6_addr32[3]),
 107                                          4, &hdata);
 108                 break;
 109         }
 110
 111         if (data)
 112                 return ntohl(*data);
 113         return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
 114 }
 115
 116 static u32 flow_get_proto(const struct sk_buff *skb, int nhoff)
 117 {
 118         __u8 *data = NULL, hdata;
 119
 120         switch (skb->protocol) {
 121         case htons(ETH_P_IP):
 122                 data = skb_header_pointer(skb,
 123                                           nhoff + offsetof(struct iphdr,
 124                                                            protocol),
 125                                           1, &hdata);
 126                 break;
 127         case htons(ETH_P_IPV6):
 128                 data = skb_header_pointer(skb,
 129                                          nhoff + offsetof(struct ipv6hdr,
 130                                                           nexthdr),
 131                                          1, &hdata);
 132                 break;
 133         }
 134         if (data)
 135                 return *data;
 136         return 0;
 137 }
 138
 139 /* helper function to get either src or dst port */
 140 static __be16 *flow_get_proto_common(const struct sk_buff *skb, int nhoff,
 141                                      __be16 *_port, int dst)
 142 {
 143         __be16 *port = NULL;
 144         int poff;
 145
 146         switch (skb->protocol) {
 147         case htons(ETH_P_IP): {
 148                 struct iphdr *iph, _iph;
 149
 150                 iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
 151                 if (!iph)
 152                         break;
 153                 if (ip_is_fragment(iph))
 154                         break;
 155                 poff = proto_ports_offset(iph->protocol);
 156                 if (poff >= 0)
 157                         port = skb_header_pointer(skb,
 158                                         nhoff + iph->ihl * 4 + poff + dst,
 159                                         sizeof(*_port), _port);
 160                 break;
 161         }
 162         case htons(ETH_P_IPV6): {
 163                 struct ipv6hdr *iph, _iph;
 164
 165                 iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
 166                 if (!iph)
 167                         break;
 168                 poff = proto_ports_offset(iph->nexthdr);
 169                 if (poff >= 0)
 170                         port = skb_header_pointer(skb,
 171                                         nhoff + sizeof(*iph) + poff + dst,
 172                                         sizeof(*_port), _port);
 173                 break;
 174         }
 175         }
 176
 177         return port;
 178 }
 179
 180 static u32 flow_get_proto_src(const struct sk_buff *skb, int nhoff)
 181 {
 182         __be16 _port, *port = flow_get_proto_common(skb, nhoff, &_port, 0);
 183
 184         if (port)
 185                 return ntohs(*port);
 186
 187         return addr_fold(skb->sk);
 188 }
 189
 190 static u32 flow_get_proto_dst(const struct sk_buff *skb, int nhoff)
 191 {
 192         __be16 _port, *port = flow_get_proto_common(skb, nhoff, &_port, 2);
 193
 194         if (port)
 195                 return ntohs(*port);
 196
 197         return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
 198 }
 199
 200 static u32 flow_get_iif(const struct sk_buff *skb)
 201 {
 202         return skb->skb_iif;
 203 }
 204
 205 static u32 flow_get_priority(const struct sk_buff *skb)
 206 {
 207         return skb->priority;
 208 }
 209
 210 static u32 flow_get_mark(const struct sk_buff *skb)
 211 {
 212         return skb->mark;
 213 }
 214
 215 static u32 flow_get_nfct(const struct sk_buff *skb)
 216 {
 217 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 218         return addr_fold(skb->nfct);
 219 #else
 220         return 0;
 221 #endif
 222 }
 223
 224 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 225 #define CTTUPLE(skb, member)                                            \
 226 ({                                                                      \
 227         enum ip_conntrack_info ctinfo;                                  \
 228         const struct nf_conn *ct = nf_ct_get(skb, &ctinfo);             \
 229         if (ct == NULL)                                                 \
 230                 goto fallback;                                          \
 231         ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member;                 \
 232 })
 233 #else
 234 #define CTTUPLE(skb, member)                                            \
 235 ({                                                                      \
 236         goto fallback;                                                  \
 237         0;                                                              \
 238 })
 239 #endif
 240
 241 static u32 flow_get_nfct_src(const struct sk_buff *skb, int nhoff)
 242 {
 243         switch (skb->protocol) {
 244         case htons(ETH_P_IP):
 245                 return ntohl(CTTUPLE(skb, src.u3.ip));
 246         case htons(ETH_P_IPV6):
 247                 return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
 248         }
 249 fallback:
 250         return flow_get_src(skb, nhoff);
 251 }
 252
 253 static u32 flow_get_nfct_dst(const struct sk_buff *skb, int nhoff)
 254 {
 255         switch (skb->protocol) {
 256         case htons(ETH_P_IP):
 257                 return ntohl(CTTUPLE(skb, dst.u3.ip));
 258         case htons(ETH_P_IPV6):
 259                 return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
 260         }
 261 fallback:
 262         return flow_get_dst(skb, nhoff);
 263 }
 264
 265 static u32 flow_get_nfct_proto_src(const struct sk_buff *skb, int nhoff)
 266 {
 267         return ntohs(CTTUPLE(skb, src.u.all));
 268 fallback:
 269         return flow_get_proto_src(skb, nhoff);
 270 }
 271
 272 static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb, int nhoff)
 273 {
 274         return ntohs(CTTUPLE(skb, dst.u.all));
 275 fallback:
 276         return flow_get_proto_dst(skb, nhoff);
 277 }
 278
 279 static u32 flow_get_rtclassid(const struct sk_buff *skb)
 280 {
 281 #ifdef CONFIG_IP_ROUTE_CLASSID
 282         if (skb_dst(skb))
 283                 return skb_dst(skb)->tclassid;
 284 #endif
 285         return 0;
 286 }
 287
 288 static u32 flow_get_skuid(const struct sk_buff *skb)
 289 {
 290         if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
 291                 return skb->sk->sk_socket->file->f_cred->fsuid;
 292         return 0;
 293 }
 294
 295 static u32 flow_get_skgid(const struct sk_buff *skb)
 296 {
 297         if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
 298                 return skb->sk->sk_socket->file->f_cred->fsgid;
 299         return 0;
 300 }
 301
 302 static u32 flow_get_vlan_tag(const struct sk_buff *skb)
 303 {
 304         u16 uninitialized_var(tag);
 305
 306         if (vlan_get_tag(skb, &tag) < 0)
 307                 return 0;
 308         return tag & VLAN_VID_MASK;
 309 }
 310
 311 static u32 flow_get_rxhash(struct sk_buff *skb)
 312 {
 313         return skb_get_rxhash(skb);
 314 }
 315
 316 static u32 flow_key_get(struct sk_buff *skb, int key)
 317 {
 318         int nhoff = skb_network_offset(skb);
 319
 320         switch (key) {
 321         case FLOW_KEY_SRC:
 322                 return flow_get_src(skb, nhoff);
 323         case FLOW_KEY_DST:
 324                 return flow_get_dst(skb, nhoff);
 325         case FLOW_KEY_PROTO:
 326                 return flow_get_proto(skb, nhoff);
 327         case FLOW_KEY_PROTO_SRC:
 328                 return flow_get_proto_src(skb, nhoff);
 329         case FLOW_KEY_PROTO_DST:
 330                 return flow_get_proto_dst(skb, nhoff);
 331         case FLOW_KEY_IIF:
 332                 return flow_get_iif(skb);
 333         case FLOW_KEY_PRIORITY:
 334                 return flow_get_priority(skb);
 335         case FLOW_KEY_MARK:
 336                 return flow_get_mark(skb);
 337         case FLOW_KEY_NFCT:
 338                 return flow_get_nfct(skb);
 339         case FLOW_KEY_NFCT_SRC:
 340                 return flow_get_nfct_src(skb, nhoff);
 341         case FLOW_KEY_NFCT_DST:
 342                 return flow_get_nfct_dst(skb, nhoff);
 343         case FLOW_KEY_NFCT_PROTO_SRC:
 344                 return flow_get_nfct_proto_src(skb, nhoff);
 345         case FLOW_KEY_NFCT_PROTO_DST:
 346                 return flow_get_nfct_proto_dst(skb, nhoff);
 347         case FLOW_KEY_RTCLASSID:
 348                 return flow_get_rtclassid(skb);
 349         case FLOW_KEY_SKUID:
 350                 return flow_get_skuid(skb);
 351         case FLOW_KEY_SKGID:
 352                 return flow_get_skgid(skb);
 353         case FLOW_KEY_VLAN_TAG:
 354                 return flow_get_vlan_tag(skb);
 355         case FLOW_KEY_RXHASH:
 356                 return flow_get_rxhash(skb);
 357         default:
 358                 WARN_ON(1);
 359                 return 0;
 360         }
 361 }
 362
 363 static int flow_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 364                          struct tcf_result *res)
 365 {
 366         struct flow_head *head = tp->root;
 367         struct flow_filter *f;
 368         u32 keymask;
 369         u32 classid;
 370         unsigned int n, key;
 371         int r;
 372
 373         list_for_each_entry(f, &head->filters, list) {
 374                 u32 keys[f->nkeys];
 375
 376                 if (!tcf_em_tree_match(skb, &f->ematches, NULL))
 377                         continue;
 378
 379                 keymask = f->keymask;
 380
 381                 for (n = 0; n < f->nkeys; n++) {
 382                         key = ffs(keymask) - 1;
 383                         keymask &= ~(1 << key);
 384                         keys[n] = flow_key_get(skb, key);
 385                 }
 386
 387                 if (f->mode == FLOW_MODE_HASH)
 388                         classid = jhash2(keys, f->nkeys, f->hashrnd);
 389                 else {
 390                         classid = keys[0];
 391                         classid = (classid & f->mask) ^ f->xor;
 392                         classid = (classid >> f->rshift) + f->addend;
 393                 }
 394
 395                 if (f->divisor)
 396                         classid %= f->divisor;
 397
 398                 res->class   = 0;
 399                 res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
 400
 401                 r = tcf_exts_exec(skb, &f->exts, res);
 402                 if (r < 0)
 403                         continue;
 404                 return r;
 405         }
 406         return -1;
 407 }
 408
 409 static void flow_perturbation(unsigned long arg)
 410 {
 411         struct flow_filter *f = (struct flow_filter *)arg;
 412
 413         get_random_bytes(&f->hashrnd, 4);
 414         if (f->perturb_period)
 415                 mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
 416 }
 417
 418 static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
 419         [TCA_FLOW_KEYS]         = { .type = NLA_U32 },
 420         [TCA_FLOW_MODE]         = { .type = NLA_U32 },
 421         [TCA_FLOW_BASECLASS]    = { .type = NLA_U32 },
 422         [TCA_FLOW_RSHIFT]       = { .type = NLA_U32 },
 423         [TCA_FLOW_ADDEND]       = { .type = NLA_U32 },
 424         [TCA_FLOW_MASK]         = { .type = NLA_U32 },
 425         [TCA_FLOW_XOR]          = { .type = NLA_U32 },
 426         [TCA_FLOW_DIVISOR]      = { .type = NLA_U32 },
 427         [TCA_FLOW_ACT]          = { .type = NLA_NESTED },
 428         [TCA_FLOW_POLICE]       = { .type = NLA_NESTED },
 429         [TCA_FLOW_EMATCHES]     = { .type = NLA_NESTED },
 430         [TCA_FLOW_PERTURB]      = { .type = NLA_U32 },
 431 };
 432
 433 static int flow_change(struct tcf_proto *tp, unsigned long base,
 434                        u32 handle, struct nlattr **tca,
 435                        unsigned long *arg)
 436 {
 437         struct flow_head *head = tp->root;
 438         struct flow_filter *f;
 439         struct nlattr *opt = tca[TCA_OPTIONS];
 440         struct nlattr *tb[TCA_FLOW_MAX + 1];
 441         struct tcf_exts e;
 442         struct tcf_ematch_tree t;
 443         unsigned int nkeys = 0;
 444         unsigned int perturb_period = 0;
 445         u32 baseclass = 0;
 446         u32 keymask = 0;
 447         u32 mode;
 448         int err;
 449
 450         if (opt == NULL)
 451                 return -EINVAL;
 452
 453         err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy);
 454         if (err < 0)
 455                 return err;
 456
 457         if (tb[TCA_FLOW_BASECLASS]) {
 458                 baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
 459                 if (TC_H_MIN(baseclass) == 0)
 460                         return -EINVAL;
 461         }
 462
 463         if (tb[TCA_FLOW_KEYS]) {
 464                 keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
 465
 466                 nkeys = hweight32(keymask);
 467                 if (nkeys == 0)
 468                         return -EINVAL;
 469
 470                 if (fls(keymask) - 1 > FLOW_KEY_MAX)
 471                         return -EOPNOTSUPP;
 472         }
 473
 474         err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &flow_ext_map);
 475         if (err < 0)
 476                 return err;
 477
 478         err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &t);
 479         if (err < 0)
 480                 goto err1;
 481
 482         f = (struct flow_filter *)*arg;
 483         if (f != NULL) {
 484                 err = -EINVAL;
 485                 if (f->handle != handle && handle)
 486                         goto err2;
 487
 488                 mode = f->mode;
 489                 if (tb[TCA_FLOW_MODE])
 490                         mode = nla_get_u32(tb[TCA_FLOW_MODE]);
 491                 if (mode != FLOW_MODE_HASH && nkeys > 1)
 492                         goto err2;
 493
 494                 if (mode == FLOW_MODE_HASH)
 495                         perturb_period = f->perturb_period;
 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         } else {
 502                 err = -EINVAL;
 503                 if (!handle)
 504                         goto err2;
 505                 if (!tb[TCA_FLOW_KEYS])
 506                         goto err2;
 507
 508                 mode = FLOW_MODE_MAP;
 509                 if (tb[TCA_FLOW_MODE])
 510                         mode = nla_get_u32(tb[TCA_FLOW_MODE]);
 511                 if (mode != FLOW_MODE_HASH && nkeys > 1)
 512                         goto err2;
 513
 514                 if (tb[TCA_FLOW_PERTURB]) {
 515                         if (mode != FLOW_MODE_HASH)
 516                                 goto err2;
 517                         perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
 518                 }
 519
 520                 if (TC_H_MAJ(baseclass) == 0)
 521                         baseclass = TC_H_MAKE(tp->q->handle, baseclass);
 522                 if (TC_H_MIN(baseclass) == 0)
 523                         baseclass = TC_H_MAKE(baseclass, 1);
 524
 525                 err = -ENOBUFS;
 526                 f = kzalloc(sizeof(*f), GFP_KERNEL);
 527                 if (f == NULL)
 528                         goto err2;
 529
 530                 f->handle = handle;
 531                 f->mask   = ~0U;
 532
 533                 get_random_bytes(&f->hashrnd, 4);
 534                 f->perturb_timer.function = flow_perturbation;
 535                 f->perturb_timer.data = (unsigned long)f;
 536                 init_timer_deferrable(&f->perturb_timer);
 537         }
 538
 539         tcf_exts_change(tp, &f->exts, &e);
 540         tcf_em_tree_change(tp, &f->ematches, &t);
 541
 542         tcf_tree_lock(tp);
 543
 544         if (tb[TCA_FLOW_KEYS]) {
 545                 f->keymask = keymask;
 546                 f->nkeys   = nkeys;
 547         }
 548
 549         f->mode = mode;
 550
 551         if (tb[TCA_FLOW_MASK])
 552                 f->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
 553         if (tb[TCA_FLOW_XOR])
 554                 f->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
 555         if (tb[TCA_FLOW_RSHIFT])
 556                 f->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
 557         if (tb[TCA_FLOW_ADDEND])
 558                 f->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
 559
 560         if (tb[TCA_FLOW_DIVISOR])
 561                 f->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
 562         if (baseclass)
 563                 f->baseclass = baseclass;
 564
 565         f->perturb_period = perturb_period;
 566         del_timer(&f->perturb_timer);
 567         if (perturb_period)
 568                 mod_timer(&f->perturb_timer, jiffies + perturb_period);
 569
 570         if (*arg == 0)
 571                 list_add_tail(&f->list, &head->filters);
 572
 573         tcf_tree_unlock(tp);
 574
 575         *arg = (unsigned long)f;
 576         return 0;
 577
 578 err2:
 579         tcf_em_tree_destroy(tp, &t);
 580 err1:
 581         tcf_exts_destroy(tp, &e);
 582         return err;
 583 }
 584
 585 static void flow_destroy_filter(struct tcf_proto *tp, struct flow_filter *f)
 586 {
 587         del_timer_sync(&f->perturb_timer);
 588         tcf_exts_destroy(tp, &f->exts);
 589         tcf_em_tree_destroy(tp, &f->ematches);
 590         kfree(f);
 591 }
 592
 593 static int flow_delete(struct tcf_proto *tp, unsigned long arg)
 594 {
 595         struct flow_filter *f = (struct flow_filter *)arg;
 596
 597         tcf_tree_lock(tp);
 598         list_del(&f->list);
 599         tcf_tree_unlock(tp);
 600         flow_destroy_filter(tp, f);
 601         return 0;
 602 }
 603
 604 static int flow_init(struct tcf_proto *tp)
 605 {
 606         struct flow_head *head;
 607
 608         head = kzalloc(sizeof(*head), GFP_KERNEL);
 609         if (head == NULL)
 610                 return -ENOBUFS;
 611         INIT_LIST_HEAD(&head->filters);
 612         tp->root = head;
 613         return 0;
 614 }
 615
 616 static void flow_destroy(struct tcf_proto *tp)
 617 {
 618         struct flow_head *head = tp->root;
 619         struct flow_filter *f, *next;
 620
 621         list_for_each_entry_safe(f, next, &head->filters, list) {
 622                 list_del(&f->list);
 623                 flow_destroy_filter(tp, f);
 624         }
 625         kfree(head);
 626 }
 627
 628 static unsigned long flow_get(struct tcf_proto *tp, u32 handle)
 629 {
 630         struct flow_head *head = tp->root;
 631         struct flow_filter *f;
 632
 633         list_for_each_entry(f, &head->filters, list)
 634                 if (f->handle == handle)
 635                         return (unsigned long)f;
 636         return 0;
 637 }
 638
 639 static void flow_put(struct tcf_proto *tp, unsigned long f)
 640 {
 641 }
 642
 643 static int flow_dump(struct tcf_proto *tp, unsigned long fh,
 644                      struct sk_buff *skb, struct tcmsg *t)
 645 {
 646         struct flow_filter *f = (struct flow_filter *)fh;
 647         struct nlattr *nest;
 648
 649         if (f == NULL)
 650                 return skb->len;
 651
 652         t->tcm_handle = f->handle;
 653
 654         nest = nla_nest_start(skb, TCA_OPTIONS);
 655         if (nest == NULL)
 656                 goto nla_put_failure;
 657
 658         NLA_PUT_U32(skb, TCA_FLOW_KEYS, f->keymask);
 659         NLA_PUT_U32(skb, TCA_FLOW_MODE, f->mode);
 660
 661         if (f->mask != ~0 || f->xor != 0) {
 662                 NLA_PUT_U32(skb, TCA_FLOW_MASK, f->mask);
 663                 NLA_PUT_U32(skb, TCA_FLOW_XOR, f->xor);
 664         }
 665         if (f->rshift)
 666                 NLA_PUT_U32(skb, TCA_FLOW_RSHIFT, f->rshift);
 667         if (f->addend)
 668                 NLA_PUT_U32(skb, TCA_FLOW_ADDEND, f->addend);
 669
 670         if (f->divisor)
 671                 NLA_PUT_U32(skb, TCA_FLOW_DIVISOR, f->divisor);
 672         if (f->baseclass)
 673                 NLA_PUT_U32(skb, TCA_FLOW_BASECLASS, f->baseclass);
 674
 675         if (f->perturb_period)
 676                 NLA_PUT_U32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ);
 677
 678         if (tcf_exts_dump(skb, &f->exts, &flow_ext_map) < 0)
 679                 goto nla_put_failure;
 680 #ifdef CONFIG_NET_EMATCH
 681         if (f->ematches.hdr.nmatches &&
 682             tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
 683                 goto nla_put_failure;
 684 #endif
 685         nla_nest_end(skb, nest);
 686
 687         if (tcf_exts_dump_stats(skb, &f->exts, &flow_ext_map) < 0)
 688                 goto nla_put_failure;
 689
 690         return skb->len;
 691
 692 nla_put_failure:
 693         nlmsg_trim(skb, nest);
 694         return -1;
 695 }
 696
 697 static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 698 {
 699         struct flow_head *head = tp->root;
 700         struct flow_filter *f;
 701
 702         list_for_each_entry(f, &head->filters, list) {
 703                 if (arg->count < arg->skip)
 704                         goto skip;
 705                 if (arg->fn(tp, (unsigned long)f, arg) < 0) {
 706                         arg->stop = 1;
 707                         break;
 708                 }
 709 skip:
 710                 arg->count++;
 711         }
 712 }
 713
 714 static struct tcf_proto_ops cls_flow_ops __read_mostly = {
 715         .kind           = "flow",
 716         .classify       = flow_classify,
 717         .init           = flow_init,
 718         .destroy        = flow_destroy,
 719         .change         = flow_change,
 720         .delete         = flow_delete,
 721         .get            = flow_get,
 722         .put            = flow_put,
 723         .dump           = flow_dump,
 724         .walk           = flow_walk,
 725         .owner          = THIS_MODULE,
 726 };
 727
 728 static int __init cls_flow_init(void)
 729 {
 730         return register_tcf_proto_ops(&cls_flow_ops);
 731 }
 732
 733 static void __exit cls_flow_exit(void)
 734 {
 735         unregister_tcf_proto_ops(&cls_flow_ops);
 736 }
 737
 738 module_init(cls_flow_init);
 739 module_exit(cls_flow_exit);
 740
 741 MODULE_LICENSE("GPL");
 742 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 743 MODULE_DESCRIPTION("TC flow classifier");