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/types.h>
  23#include <linux/kernel.h>
  24#include <linux/string.h>
  25#include <linux/errno.h>
  26#include <linux/skbuff.h>
  27#include <net/netlink.h>
  28#include <net/act_api.h>
  29#include <net/pkt_cls.h>
  30
  31#define HTSIZE (PAGE_SIZE/sizeof(struct fw_filter *))
  32
  33struct fw_head
  34{
  35        struct fw_filter *ht[HTSIZE];
  36        u32 mask;
  37};
  38
  39struct fw_filter
  40{
  41        struct fw_filter        *next;
  42        u32                     id;
  43        struct tcf_result       res;
  44#ifdef CONFIG_NET_CLS_IND
  45        char                    indev[IFNAMSIZ];
  46#endif /* CONFIG_NET_CLS_IND */
  47        struct tcf_exts         exts;
  48};
  49
  50static const struct tcf_ext_map fw_ext_map = {
  51        .action = TCA_FW_ACT,
  52        .police = TCA_FW_POLICE
  53};
  54
  55static __inline__ int fw_hash(u32 handle)
  56{
  57        if (HTSIZE == 4096)
  58                return ((handle >> 24) & 0xFFF) ^
  59                       ((handle >> 12) & 0xFFF) ^
  60                       (handle & 0xFFF);
  61        else if (HTSIZE == 2048)
  62                return ((handle >> 22) & 0x7FF) ^
  63                       ((handle >> 11) & 0x7FF) ^
  64                       (handle & 0x7FF);
  65        else if (HTSIZE == 1024)
  66                return ((handle >> 20) & 0x3FF) ^
  67                       ((handle >> 10) & 0x3FF) ^
  68                       (handle & 0x3FF);
  69        else if (HTSIZE == 512)
  70                return (handle >> 27) ^
  71                       ((handle >> 18) & 0x1FF) ^
  72                       ((handle >> 9) & 0x1FF) ^
  73                       (handle & 0x1FF);
  74        else if (HTSIZE == 256) {
  75                u8 *t = (u8 *) &handle;
  76                return t[0] ^ t[1] ^ t[2] ^ t[3];
  77        } else
  78                return handle & (HTSIZE - 1);
  79}
  80
  81static int fw_classify(struct sk_buff *skb, struct tcf_proto *tp,
  82                          struct tcf_result *res)
  83{
  84        struct fw_head *head = (struct fw_head*)tp->root;
  85        struct fw_filter *f;
  86        int r;
  87        u32 id = skb->mark;
  88
  89        if (head != NULL) {
  90                id &= head->mask;
  91                for (f=head->ht[fw_hash(id)]; f; f=f->next) {
  92                        if (f->id == id) {
  93                                *res = f->res;
  94#ifdef CONFIG_NET_CLS_IND
  95                                if (!tcf_match_indev(skb, f->indev))
  96                                        continue;
  97#endif /* CONFIG_NET_CLS_IND */
  98                                r = tcf_exts_exec(skb, &f->exts, res);
  99                                if (r < 0)
 100                                        continue;
 101
 102                                return r;
 103                        }
 104                }
 105        } else {
 106                /* old method */
 107                if (id && (TC_H_MAJ(id) == 0 || !(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 inline void
 142fw_delete_filter(struct tcf_proto *tp, struct fw_filter *f)
 143{
 144        tcf_unbind_filter(tp, &f->res);
 145        tcf_exts_destroy(tp, &f->exts);
 146        kfree(f);
 147}
 148
 149static void fw_destroy(struct tcf_proto *tp)
 150{
 151        struct fw_head *head = tp->root;
 152        struct fw_filter *f;
 153        int h;
 154
 155        if (head == NULL)
 156                return;
 157
 158        for (h=0; h<HTSIZE; h++) {
 159                while ((f=head->ht[h]) != NULL) {
 160                        head->ht[h] = f->next;
 161                        fw_delete_filter(tp, f);
 162                }
 163        }
 164        kfree(head);
 165}
 166
 167static int fw_delete(struct tcf_proto *tp, unsigned long arg)
 168{
 169        struct fw_head *head = (struct fw_head*)tp->root;
 170        struct fw_filter *f = (struct fw_filter*)arg;
 171        struct fw_filter **fp;
 172
 173        if (head == NULL || f == NULL)
 174                goto out;
 175
 176        for (fp=&head->ht[fw_hash(f->id)]; *fp; fp = &(*fp)->next) {
 177                if (*fp == f) {
 178                        tcf_tree_lock(tp);
 179                        *fp = f->next;
 180                        tcf_tree_unlock(tp);
 181                        fw_delete_filter(tp, f);
 182                        return 0;
 183                }
 184        }
 185out:
 186        return -EINVAL;
 187}
 188
 189static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
 190        [TCA_FW_CLASSID]        = { .type = NLA_U32 },
 191        [TCA_FW_INDEV]          = { .type = NLA_STRING, .len = IFNAMSIZ },
 192        [TCA_FW_MASK]           = { .type = NLA_U32 },
 193};
 194
 195static int
 196fw_change_attrs(struct tcf_proto *tp, struct fw_filter *f,
 197        struct nlattr **tb, struct nlattr **tca, unsigned long base)
 198{
 199        struct fw_head *head = (struct fw_head *)tp->root;
 200        struct tcf_exts e;
 201        u32 mask;
 202        int err;
 203
 204        err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &fw_ext_map);
 205        if (err < 0)
 206                return err;
 207
 208        err = -EINVAL;
 209        if (tb[TCA_FW_CLASSID]) {
 210                f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
 211                tcf_bind_filter(tp, &f->res, base);
 212        }
 213
 214#ifdef CONFIG_NET_CLS_IND
 215        if (tb[TCA_FW_INDEV]) {
 216                err = tcf_change_indev(tp, f->indev, tb[TCA_FW_INDEV]);
 217                if (err < 0)
 218                        goto errout;
 219        }
 220#endif /* CONFIG_NET_CLS_IND */
 221
 222        if (tb[TCA_FW_MASK]) {
 223                mask = nla_get_u32(tb[TCA_FW_MASK]);
 224                if (mask != head->mask)
 225                        goto errout;
 226        } else if (head->mask != 0xFFFFFFFF)
 227                goto errout;
 228
 229        tcf_exts_change(tp, &f->exts, &e);
 230
 231        return 0;
 232errout:
 233        tcf_exts_destroy(tp, &e);
 234        return err;
 235}
 236
 237static int fw_change(struct tcf_proto *tp, unsigned long base,
 238                     u32 handle,
 239                     struct nlattr **tca,
 240                     unsigned long *arg)
 241{
 242        struct fw_head *head = (struct fw_head*)tp->root;
 243        struct fw_filter *f = (struct fw_filter *) *arg;
 244        struct nlattr *opt = tca[TCA_OPTIONS];
 245        struct nlattr *tb[TCA_FW_MAX + 1];
 246        int err;
 247
 248        if (!opt)
 249                return handle ? -EINVAL : 0;
 250
 251        err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
 252        if (err < 0)
 253                return err;
 254
 255        if (f != NULL) {
 256                if (f->id != handle && handle)
 257                        return -EINVAL;
 258                return fw_change_attrs(tp, f, tb, tca, base);
 259        }
 260
 261        if (!handle)
 262                return -EINVAL;
 263
 264        if (head == NULL) {
 265                u32 mask = 0xFFFFFFFF;
 266                if (tb[TCA_FW_MASK])
 267                        mask = nla_get_u32(tb[TCA_FW_MASK]);
 268
 269                head = kzalloc(sizeof(struct fw_head), GFP_KERNEL);
 270                if (head == NULL)
 271                        return -ENOBUFS;
 272                head->mask = mask;
 273
 274                tcf_tree_lock(tp);
 275                tp->root = head;
 276                tcf_tree_unlock(tp);
 277        }
 278
 279        f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
 280        if (f == NULL)
 281                return -ENOBUFS;
 282
 283        f->id = handle;
 284
 285        err = fw_change_attrs(tp, f, tb, tca, base);
 286        if (err < 0)
 287                goto errout;
 288
 289        f->next = head->ht[fw_hash(handle)];
 290        tcf_tree_lock(tp);
 291        head->ht[fw_hash(handle)] = f;
 292        tcf_tree_unlock(tp);
 293
 294        *arg = (unsigned long)f;
 295        return 0;
 296
 297errout:
 298        kfree(f);
 299        return err;
 300}
 301
 302static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 303{
 304        struct fw_head *head = (struct fw_head*)tp->root;
 305        int h;
 306
 307        if (head == NULL)
 308                arg->stop = 1;
 309
 310        if (arg->stop)
 311                return;
 312
 313        for (h = 0; h < HTSIZE; h++) {
 314                struct fw_filter *f;
 315
 316                for (f = head->ht[h]; f; f = f->next) {
 317                        if (arg->count < arg->skip) {
 318                                arg->count++;
 319                                continue;
 320                        }
 321                        if (arg->fn(tp, (unsigned long)f, arg) < 0) {
 322                                arg->stop = 1;
 323                                return;
 324                        }
 325                        arg->count++;
 326                }
 327        }
 328}
 329
 330static int fw_dump(struct tcf_proto *tp, unsigned long fh,
 331                   struct sk_buff *skb, struct tcmsg *t)
 332{
 333        struct fw_head *head = (struct fw_head *)tp->root;
 334        struct fw_filter *f = (struct fw_filter*)fh;
 335        unsigned char *b = skb_tail_pointer(skb);
 336        struct nlattr *nest;
 337
 338        if (f == NULL)
 339                return skb->len;
 340
 341        t->tcm_handle = f->id;
 342
 343        if (!f->res.classid && !tcf_exts_is_available(&f->exts))
 344                return skb->len;
 345
 346        nest = nla_nest_start(skb, TCA_OPTIONS);
 347        if (nest == NULL)
 348                goto nla_put_failure;
 349
 350        if (f->res.classid)
 351                NLA_PUT_U32(skb, TCA_FW_CLASSID, f->res.classid);
 352#ifdef CONFIG_NET_CLS_IND
 353        if (strlen(f->indev))
 354                NLA_PUT_STRING(skb, TCA_FW_INDEV, f->indev);
 355#endif /* CONFIG_NET_CLS_IND */
 356        if (head->mask != 0xFFFFFFFF)
 357                NLA_PUT_U32(skb, TCA_FW_MASK, head->mask);
 358
 359        if (tcf_exts_dump(skb, &f->exts, &fw_ext_map) < 0)
 360                goto nla_put_failure;
 361
 362        nla_nest_end(skb, nest);
 363
 364        if (tcf_exts_dump_stats(skb, &f->exts, &fw_ext_map) < 0)
 365                goto nla_put_failure;
 366
 367        return skb->len;
 368
 369nla_put_failure:
 370        nlmsg_trim(skb, b);
 371        return -1;
 372}
 373
 374static struct tcf_proto_ops cls_fw_ops __read_mostly = {
 375        .kind           =       "fw",
 376        .classify       =       fw_classify,
 377        .init           =       fw_init,
 378        .destroy        =       fw_destroy,
 379        .get            =       fw_get,
 380        .put            =       fw_put,
 381        .change         =       fw_change,
 382        .delete         =       fw_delete,
 383        .walk           =       fw_walk,
 384        .dump           =       fw_dump,
 385        .owner          =       THIS_MODULE,
 386};
 387
 388static int __init init_fw(void)
 389{
 390        return register_tcf_proto_ops(&cls_fw_ops);
 391}
 392
 393static void __exit exit_fw(void)
 394{
 395        unregister_tcf_proto_ops(&cls_fw_ops);
 396}
 397
 398module_init(init_fw)
 399module_exit(exit_fw)
 400MODULE_LICENSE("GPL");
 401