linux/net/sched/cls_fw.c
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   1/*
   2 * net/sched/cls_fw.c   Classifier mapping ipchains' fwmark to traffic class.
   3 *
   4 *              This program is free software; you can redistribute it and/or
   5 *              modify it under the terms of the GNU General Public License
   6 *              as published by the Free Software Foundation; either version
   7 *              2 of the License, or (at your option) any later version.
   8 *
   9 * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10 *
  11 * Changes:
  12 * Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_walk off by one
  13 * Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_delete killed all the filter (and kernel).
  14 * Alex <alex@pilotsoft.com> : 2004xxyy: Added Action extension
  15 *
  16 * JHS: We should remove the CONFIG_NET_CLS_IND from here
  17 * eventually when the meta match extension is made available
  18 *
  19 */
  20
  21#include <linux/module.h>
  22#include <linux/slab.h>
  23#include <linux/types.h>
  24#include <linux/kernel.h>
  25#include <linux/string.h>
  26#include <linux/errno.h>
  27#include <linux/skbuff.h>
  28#include <net/netlink.h>
  29#include <net/act_api.h>
  30#include <net/pkt_cls.h>
  31
  32#define HTSIZE (PAGE_SIZE/sizeof(struct fw_filter *))
  33
  34struct fw_head {
  35        struct fw_filter *ht[HTSIZE];
  36        u32 mask;
  37};
  38
  39struct fw_filter {
  40        struct fw_filter        *next;
  41        u32                     id;
  42        struct tcf_result       res;
  43#ifdef CONFIG_NET_CLS_IND
  44        char                    indev[IFNAMSIZ];
  45#endif /* CONFIG_NET_CLS_IND */
  46        struct tcf_exts         exts;
  47};
  48
  49static const struct tcf_ext_map fw_ext_map = {
  50        .action = TCA_FW_ACT,
  51        .police = TCA_FW_POLICE
  52};
  53
  54static inline int fw_hash(u32 handle)
  55{
  56        if (HTSIZE == 4096)
  57                return ((handle >> 24) & 0xFFF) ^
  58                       ((handle >> 12) & 0xFFF) ^
  59                       (handle & 0xFFF);
  60        else if (HTSIZE == 2048)
  61                return ((handle >> 22) & 0x7FF) ^
  62                       ((handle >> 11) & 0x7FF) ^
  63                       (handle & 0x7FF);
  64        else if (HTSIZE == 1024)
  65                return ((handle >> 20) & 0x3FF) ^
  66                       ((handle >> 10) & 0x3FF) ^
  67                       (handle & 0x3FF);
  68        else if (HTSIZE == 512)
  69                return (handle >> 27) ^
  70                       ((handle >> 18) & 0x1FF) ^
  71                       ((handle >> 9) & 0x1FF) ^
  72                       (handle & 0x1FF);
  73        else if (HTSIZE == 256) {
  74                u8 *t = (u8 *) &handle;
  75                return t[0] ^ t[1] ^ t[2] ^ t[3];
  76        } else
  77                return handle & (HTSIZE - 1);
  78}
  79
  80static int fw_classify(struct sk_buff *skb, const struct tcf_proto *tp,
  81                          struct tcf_result *res)
  82{
  83        struct fw_head *head = (struct fw_head *)tp->root;
  84        struct fw_filter *f;
  85        int r;
  86        u32 id = skb->mark;
  87
  88        if (head != NULL) {
  89                id &= head->mask;
  90                for (f = head->ht[fw_hash(id)]; f; f = f->next) {
  91                        if (f->id == id) {
  92                                *res = f->res;
  93#ifdef CONFIG_NET_CLS_IND
  94                                if (!tcf_match_indev(skb, f->indev))
  95                                        continue;
  96#endif /* CONFIG_NET_CLS_IND */
  97                                r = tcf_exts_exec(skb, &f->exts, res);
  98                                if (r < 0)
  99                                        continue;
 100
 101                                return r;
 102                        }
 103                }
 104        } else {
 105                /* old method */
 106                if (id && (TC_H_MAJ(id) == 0 ||
 107                           !(TC_H_MAJ(id ^ tp->q->handle)))) {
 108                        res->classid = id;
 109                        res->class = 0;
 110                        return 0;
 111                }
 112        }
 113
 114        return -1;
 115}
 116
 117static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
 118{
 119        struct fw_head *head = (struct fw_head *)tp->root;
 120        struct fw_filter *f;
 121
 122        if (head == NULL)
 123                return 0;
 124
 125        for (f = head->ht[fw_hash(handle)]; f; f = f->next) {
 126                if (f->id == handle)
 127                        return (unsigned long)f;
 128        }
 129        return 0;
 130}
 131
 132static void fw_put(struct tcf_proto *tp, unsigned long f)
 133{
 134}
 135
 136static int fw_init(struct tcf_proto *tp)
 137{
 138        return 0;
 139}
 140
 141static void fw_delete_filter(struct tcf_proto *tp, struct fw_filter *f)
 142{
 143        tcf_unbind_filter(tp, &f->res);
 144        tcf_exts_destroy(tp, &f->exts);
 145        kfree(f);
 146}
 147
 148static void fw_destroy(struct tcf_proto *tp)
 149{
 150        struct fw_head *head = tp->root;
 151        struct fw_filter *f;
 152        int h;
 153
 154        if (head == NULL)
 155                return;
 156
 157        for (h = 0; h < HTSIZE; h++) {
 158                while ((f = head->ht[h]) != NULL) {
 159                        head->ht[h] = f->next;
 160                        fw_delete_filter(tp, f);
 161                }
 162        }
 163        kfree(head);
 164}
 165
 166static int fw_delete(struct tcf_proto *tp, unsigned long arg)
 167{
 168        struct fw_head *head = (struct fw_head *)tp->root;
 169        struct fw_filter *f = (struct fw_filter *)arg;
 170        struct fw_filter **fp;
 171
 172        if (head == NULL || f == NULL)
 173                goto out;
 174
 175        for (fp = &head->ht[fw_hash(f->id)]; *fp; fp = &(*fp)->next) {
 176                if (*fp == f) {
 177                        tcf_tree_lock(tp);
 178                        *fp = f->next;
 179                        tcf_tree_unlock(tp);
 180                        fw_delete_filter(tp, f);
 181                        return 0;
 182                }
 183        }
 184out:
 185        return -EINVAL;
 186}
 187
 188static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
 189        [TCA_FW_CLASSID]        = { .type = NLA_U32 },
 190        [TCA_FW_INDEV]          = { .type = NLA_STRING, .len = IFNAMSIZ },
 191        [TCA_FW_MASK]           = { .type = NLA_U32 },
 192};
 193
 194static int
 195fw_change_attrs(struct tcf_proto *tp, struct fw_filter *f,
 196        struct nlattr **tb, struct nlattr **tca, unsigned long base)
 197{
 198        struct fw_head *head = (struct fw_head *)tp->root;
 199        struct tcf_exts e;
 200        u32 mask;
 201        int err;
 202
 203        err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &fw_ext_map);
 204        if (err < 0)
 205                return err;
 206
 207        err = -EINVAL;
 208        if (tb[TCA_FW_CLASSID]) {
 209                f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
 210                tcf_bind_filter(tp, &f->res, base);
 211        }
 212
 213#ifdef CONFIG_NET_CLS_IND
 214        if (tb[TCA_FW_INDEV]) {
 215                err = tcf_change_indev(tp, f->indev, tb[TCA_FW_INDEV]);
 216                if (err < 0)
 217                        goto errout;
 218        }
 219#endif /* CONFIG_NET_CLS_IND */
 220
 221        if (tb[TCA_FW_MASK]) {
 222                mask = nla_get_u32(tb[TCA_FW_MASK]);
 223                if (mask != head->mask)
 224                        goto errout;
 225        } else if (head->mask != 0xFFFFFFFF)
 226                goto errout;
 227
 228        tcf_exts_change(tp, &f->exts, &e);
 229
 230        return 0;
 231errout:
 232        tcf_exts_destroy(tp, &e);
 233        return err;
 234}
 235
 236static int fw_change(struct tcf_proto *tp, unsigned long base,
 237                     u32 handle,
 238                     struct nlattr **tca,
 239                     unsigned long *arg)
 240{
 241        struct fw_head *head = (struct fw_head *)tp->root;
 242        struct fw_filter *f = (struct fw_filter *) *arg;
 243        struct nlattr *opt = tca[TCA_OPTIONS];
 244        struct nlattr *tb[TCA_FW_MAX + 1];
 245        int err;
 246
 247        if (!opt)
 248                return handle ? -EINVAL : 0;
 249
 250        err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
 251        if (err < 0)
 252                return err;
 253
 254        if (f != NULL) {
 255                if (f->id != handle && handle)
 256                        return -EINVAL;
 257                return fw_change_attrs(tp, f, tb, tca, base);
 258        }
 259
 260        if (!handle)
 261                return -EINVAL;
 262
 263        if (head == NULL) {
 264                u32 mask = 0xFFFFFFFF;
 265                if (tb[TCA_FW_MASK])
 266                        mask = nla_get_u32(tb[TCA_FW_MASK]);
 267
 268                head = kzalloc(sizeof(struct fw_head), GFP_KERNEL);
 269                if (head == NULL)
 270                        return -ENOBUFS;
 271                head->mask = mask;
 272
 273                tcf_tree_lock(tp);
 274                tp->root = head;
 275                tcf_tree_unlock(tp);
 276        }
 277
 278        f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
 279        if (f == NULL)
 280                return -ENOBUFS;
 281
 282        f->id = handle;
 283
 284        err = fw_change_attrs(tp, f, tb, tca, base);
 285        if (err < 0)
 286                goto errout;
 287
 288        f->next = head->ht[fw_hash(handle)];
 289        tcf_tree_lock(tp);
 290        head->ht[fw_hash(handle)] = f;
 291        tcf_tree_unlock(tp);
 292
 293        *arg = (unsigned long)f;
 294        return 0;
 295
 296errout:
 297        kfree(f);
 298        return err;
 299}
 300
 301static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 302{
 303        struct fw_head *head = (struct fw_head *)tp->root;
 304        int h;
 305
 306        if (head == NULL)
 307                arg->stop = 1;
 308
 309        if (arg->stop)
 310                return;
 311
 312        for (h = 0; h < HTSIZE; h++) {
 313                struct fw_filter *f;
 314
 315                for (f = head->ht[h]; f; f = f->next) {
 316                        if (arg->count < arg->skip) {
 317                                arg->count++;
 318                                continue;
 319                        }
 320                        if (arg->fn(tp, (unsigned long)f, arg) < 0) {
 321                                arg->stop = 1;
 322                                return;
 323                        }
 324                        arg->count++;
 325                }
 326        }
 327}
 328
 329static int fw_dump(struct tcf_proto *tp, unsigned long fh,
 330                   struct sk_buff *skb, struct tcmsg *t)
 331{
 332        struct fw_head *head = (struct fw_head *)tp->root;
 333        struct fw_filter *f = (struct fw_filter *)fh;
 334        unsigned char *b = skb_tail_pointer(skb);
 335        struct nlattr *nest;
 336
 337        if (f == NULL)
 338                return skb->len;
 339
 340        t->tcm_handle = f->id;
 341
 342        if (!f->res.classid && !tcf_exts_is_available(&f->exts))
 343                return skb->len;
 344
 345        nest = nla_nest_start(skb, TCA_OPTIONS);
 346        if (nest == NULL)
 347                goto nla_put_failure;
 348
 349        if (f->res.classid &&
 350            nla_put_u32(skb, TCA_FW_CLASSID, f->res.classid))
 351                goto nla_put_failure;
 352#ifdef CONFIG_NET_CLS_IND
 353        if (strlen(f->indev) &&
 354            nla_put_string(skb, TCA_FW_INDEV, f->indev))
 355                goto nla_put_failure;
 356#endif /* CONFIG_NET_CLS_IND */
 357        if (head->mask != 0xFFFFFFFF &&
 358            nla_put_u32(skb, TCA_FW_MASK, head->mask))
 359                goto nla_put_failure;
 360
 361        if (tcf_exts_dump(skb, &f->exts, &fw_ext_map) < 0)
 362                goto nla_put_failure;
 363
 364        nla_nest_end(skb, nest);
 365
 366        if (tcf_exts_dump_stats(skb, &f->exts, &fw_ext_map) < 0)
 367                goto nla_put_failure;
 368
 369        return skb->len;
 370
 371nla_put_failure:
 372        nlmsg_trim(skb, b);
 373        return -1;
 374}
 375
 376static struct tcf_proto_ops cls_fw_ops __read_mostly = {
 377        .kind           =       "fw",
 378        .classify       =       fw_classify,
 379        .init           =       fw_init,
 380        .destroy        =       fw_destroy,
 381        .get            =       fw_get,
 382        .put            =       fw_put,
 383        .change         =       fw_change,
 384        .delete         =       fw_delete,
 385        .walk           =       fw_walk,
 386        .dump           =       fw_dump,
 387        .owner          =       THIS_MODULE,
 388};
 389
 390static int __init init_fw(void)
 391{
 392        return register_tcf_proto_ops(&cls_fw_ops);
 393}
 394
 395static void __exit exit_fw(void)
 396{
 397        unregister_tcf_proto_ops(&cls_fw_ops);
 398}
 399
 400module_init(init_fw)
 401module_exit(exit_fw)
 402MODULE_LICENSE("GPL");
 403
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