net/sched/cls_fw.c

   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
  34 struct fw_head
  35 {
  36         struct fw_filter *ht[HTSIZE];
  37         u32 mask;
  38 };
  39
  40 struct fw_filter
  41 {
  42         struct fw_filter        *next;
  43         u32                     id;
  44         struct tcf_result       res;
  45 #ifdef CONFIG_NET_CLS_IND
  46         char                    indev[IFNAMSIZ];
  47 #endif /* CONFIG_NET_CLS_IND */
  48         struct tcf_exts         exts;
  49 };
  50
  51 static const struct tcf_ext_map fw_ext_map = {
  52         .action = TCA_FW_ACT,
  53         .police = TCA_FW_POLICE
  54 };
  55
  56 static __inline__ int fw_hash(u32 handle)
  57 {
  58         if (HTSIZE == 4096)
  59                 return ((handle >> 24) & 0xFFF) ^
  60                        ((handle >> 12) & 0xFFF) ^
  61                        (handle & 0xFFF);
  62         else if (HTSIZE == 2048)
  63                 return ((handle >> 22) & 0x7FF) ^
  64                        ((handle >> 11) & 0x7FF) ^
  65                        (handle & 0x7FF);
  66         else if (HTSIZE == 1024)
  67                 return ((handle >> 20) & 0x3FF) ^
  68                        ((handle >> 10) & 0x3FF) ^
  69                        (handle & 0x3FF);
  70         else if (HTSIZE == 512)
  71                 return (handle >> 27) ^
  72                        ((handle >> 18) & 0x1FF) ^
  73                        ((handle >> 9) & 0x1FF) ^
  74                        (handle & 0x1FF);
  75         else if (HTSIZE == 256) {
  76                 u8 *t = (u8 *) &handle;
  77                 return t[0] ^ t[1] ^ t[2] ^ t[3];
  78         } else
  79                 return handle & (HTSIZE - 1);
  80 }
  81
  82 static int fw_classify(struct sk_buff *skb, struct tcf_proto *tp,
  83                           struct tcf_result *res)
  84 {
  85         struct fw_head *head = (struct fw_head*)tp->root;
  86         struct fw_filter *f;
  87         int r;
  88         u32 id = skb->mark;
  89
  90         if (head != NULL) {
  91                 id &= head->mask;
  92                 for (f=head->ht[fw_hash(id)]; f; f=f->next) {
  93                         if (f->id == id) {
  94                                 *res = f->res;
  95 #ifdef CONFIG_NET_CLS_IND
  96                                 if (!tcf_match_indev(skb, f->indev))
  97                                         continue;
  98 #endif /* CONFIG_NET_CLS_IND */
  99                                 r = tcf_exts_exec(skb, &f->exts, res);
 100                                 if (r < 0)
 101                                         continue;
 102
 103                                 return r;
 104                         }
 105                 }
 106         } else {
 107                 /* old method */
 108                 if (id && (TC_H_MAJ(id) == 0 || !(TC_H_MAJ(id^tp->q->handle)))) {
 109                         res->classid = id;
 110                         res->class = 0;
 111                         return 0;
 112                 }
 113         }
 114
 115         return -1;
 116 }
 117
 118 static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
 119 {
 120         struct fw_head *head = (struct fw_head*)tp->root;
 121         struct fw_filter *f;
 122
 123         if (head == NULL)
 124                 return 0;
 125
 126         for (f=head->ht[fw_hash(handle)]; f; f=f->next) {
 127                 if (f->id == handle)
 128                         return (unsigned long)f;
 129         }
 130         return 0;
 131 }
 132
 133 static void fw_put(struct tcf_proto *tp, unsigned long f)
 134 {
 135 }
 136
 137 static int fw_init(struct tcf_proto *tp)
 138 {
 139         return 0;
 140 }
 141
 142 static inline void
 143 fw_delete_filter(struct tcf_proto *tp, struct fw_filter *f)
 144 {
 145         tcf_unbind_filter(tp, &f->res);
 146         tcf_exts_destroy(tp, &f->exts);
 147         kfree(f);
 148 }
 149
 150 static void fw_destroy(struct tcf_proto *tp)
 151 {
 152         struct fw_head *head = tp->root;
 153         struct fw_filter *f;
 154         int h;
 155
 156         if (head == NULL)
 157                 return;
 158
 159         for (h=0; h<HTSIZE; h++) {
 160                 while ((f=head->ht[h]) != NULL) {
 161                         head->ht[h] = f->next;
 162                         fw_delete_filter(tp, f);
 163                 }
 164         }
 165         kfree(head);
 166 }
 167
 168 static int fw_delete(struct tcf_proto *tp, unsigned long arg)
 169 {
 170         struct fw_head *head = (struct fw_head*)tp->root;
 171         struct fw_filter *f = (struct fw_filter*)arg;
 172         struct fw_filter **fp;
 173
 174         if (head == NULL || f == NULL)
 175                 goto out;
 176
 177         for (fp=&head->ht[fw_hash(f->id)]; *fp; fp = &(*fp)->next) {
 178                 if (*fp == f) {
 179                         tcf_tree_lock(tp);
 180                         *fp = f->next;
 181                         tcf_tree_unlock(tp);
 182                         fw_delete_filter(tp, f);
 183                         return 0;
 184                 }
 185         }
 186 out:
 187         return -EINVAL;
 188 }
 189
 190 static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
 191         [TCA_FW_CLASSID]        = { .type = NLA_U32 },
 192         [TCA_FW_INDEV]          = { .type = NLA_STRING, .len = IFNAMSIZ },
 193         [TCA_FW_MASK]           = { .type = NLA_U32 },
 194 };
 195
 196 static int
 197 fw_change_attrs(struct tcf_proto *tp, struct fw_filter *f,
 198         struct nlattr **tb, struct nlattr **tca, unsigned long base)
 199 {
 200         struct fw_head *head = (struct fw_head *)tp->root;
 201         struct tcf_exts e;
 202         u32 mask;
 203         int err;
 204
 205         err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &fw_ext_map);
 206         if (err < 0)
 207                 return err;
 208
 209         err = -EINVAL;
 210         if (tb[TCA_FW_CLASSID]) {
 211                 f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
 212                 tcf_bind_filter(tp, &f->res, base);
 213         }
 214
 215 #ifdef CONFIG_NET_CLS_IND
 216         if (tb[TCA_FW_INDEV]) {
 217                 err = tcf_change_indev(tp, f->indev, tb[TCA_FW_INDEV]);
 218                 if (err < 0)
 219                         goto errout;
 220         }
 221 #endif /* CONFIG_NET_CLS_IND */
 222
 223         if (tb[TCA_FW_MASK]) {
 224                 mask = nla_get_u32(tb[TCA_FW_MASK]);
 225                 if (mask != head->mask)
 226                         goto errout;
 227         } else if (head->mask != 0xFFFFFFFF)
 228                 goto errout;
 229
 230         tcf_exts_change(tp, &f->exts, &e);
 231
 232         return 0;
 233 errout:
 234         tcf_exts_destroy(tp, &e);
 235         return err;
 236 }
 237
 238 static int fw_change(struct tcf_proto *tp, unsigned long base,
 239                      u32 handle,
 240                      struct nlattr **tca,
 241                      unsigned long *arg)
 242 {
 243         struct fw_head *head = (struct fw_head*)tp->root;
 244         struct fw_filter *f = (struct fw_filter *) *arg;
 245         struct nlattr *opt = tca[TCA_OPTIONS];
 246         struct nlattr *tb[TCA_FW_MAX + 1];
 247         int err;
 248
 249         if (!opt)
 250                 return handle ? -EINVAL : 0;
 251
 252         err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
 253         if (err < 0)
 254                 return err;
 255
 256         if (f != NULL) {
 257                 if (f->id != handle && handle)
 258                         return -EINVAL;
 259                 return fw_change_attrs(tp, f, tb, tca, base);
 260         }
 261
 262         if (!handle)
 263                 return -EINVAL;
 264
 265         if (head == NULL) {
 266                 u32 mask = 0xFFFFFFFF;
 267                 if (tb[TCA_FW_MASK])
 268                         mask = nla_get_u32(tb[TCA_FW_MASK]);
 269
 270                 head = kzalloc(sizeof(struct fw_head), GFP_KERNEL);
 271                 if (head == NULL)
 272                         return -ENOBUFS;
 273                 head->mask = mask;
 274
 275                 tcf_tree_lock(tp);
 276                 tp->root = head;
 277                 tcf_tree_unlock(tp);
 278         }
 279
 280         f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
 281         if (f == NULL)
 282                 return -ENOBUFS;
 283
 284         f->id = handle;
 285
 286         err = fw_change_attrs(tp, f, tb, tca, base);
 287         if (err < 0)
 288                 goto errout;
 289
 290         f->next = head->ht[fw_hash(handle)];
 291         tcf_tree_lock(tp);
 292         head->ht[fw_hash(handle)] = f;
 293         tcf_tree_unlock(tp);
 294
 295         *arg = (unsigned long)f;
 296         return 0;
 297
 298 errout:
 299         kfree(f);
 300         return err;
 301 }
 302
 303 static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 304 {
 305         struct fw_head *head = (struct fw_head*)tp->root;
 306         int h;
 307
 308         if (head == NULL)
 309                 arg->stop = 1;
 310
 311         if (arg->stop)
 312                 return;
 313
 314         for (h = 0; h < HTSIZE; h++) {
 315                 struct fw_filter *f;
 316
 317                 for (f = head->ht[h]; f; f = f->next) {
 318                         if (arg->count < arg->skip) {
 319                                 arg->count++;
 320                                 continue;
 321                         }
 322                         if (arg->fn(tp, (unsigned long)f, arg) < 0) {
 323                                 arg->stop = 1;
 324                                 return;
 325                         }
 326                         arg->count++;
 327                 }
 328         }
 329 }
 330
 331 static int fw_dump(struct tcf_proto *tp, unsigned long fh,
 332                    struct sk_buff *skb, struct tcmsg *t)
 333 {
 334         struct fw_head *head = (struct fw_head *)tp->root;
 335         struct fw_filter *f = (struct fw_filter*)fh;
 336         unsigned char *b = skb_tail_pointer(skb);
 337         struct nlattr *nest;
 338
 339         if (f == NULL)
 340                 return skb->len;
 341
 342         t->tcm_handle = f->id;
 343
 344         if (!f->res.classid && !tcf_exts_is_available(&f->exts))
 345                 return skb->len;
 346
 347         nest = nla_nest_start(skb, TCA_OPTIONS);
 348         if (nest == NULL)
 349                 goto nla_put_failure;
 350
 351         if (f->res.classid)
 352                 NLA_PUT_U32(skb, TCA_FW_CLASSID, f->res.classid);
 353 #ifdef CONFIG_NET_CLS_IND
 354         if (strlen(f->indev))
 355                 NLA_PUT_STRING(skb, TCA_FW_INDEV, f->indev);
 356 #endif /* CONFIG_NET_CLS_IND */
 357         if (head->mask != 0xFFFFFFFF)
 358                 NLA_PUT_U32(skb, TCA_FW_MASK, head->mask);
 359
 360         if (tcf_exts_dump(skb, &f->exts, &fw_ext_map) < 0)
 361                 goto nla_put_failure;
 362
 363         nla_nest_end(skb, nest);
 364
 365         if (tcf_exts_dump_stats(skb, &f->exts, &fw_ext_map) < 0)
 366                 goto nla_put_failure;
 367
 368         return skb->len;
 369
 370 nla_put_failure:
 371         nlmsg_trim(skb, b);
 372         return -1;
 373 }
 374
 375 static struct tcf_proto_ops cls_fw_ops __read_mostly = {
 376         .kind           =       "fw",
 377         .classify       =       fw_classify,
 378         .init           =       fw_init,
 379         .destroy        =       fw_destroy,
 380         .get            =       fw_get,
 381         .put            =       fw_put,
 382         .change         =       fw_change,
 383         .delete         =       fw_delete,
 384         .walk           =       fw_walk,
 385         .dump           =       fw_dump,
 386         .owner          =       THIS_MODULE,
 387 };
 388
 389 static int __init init_fw(void)
 390 {
 391         return register_tcf_proto_ops(&cls_fw_ops);
 392 }
 393
 394 static void __exit exit_fw(void)
 395 {
 396         unregister_tcf_proto_ops(&cls_fw_ops);
 397 }
 398
 399 module_init(init_fw)
 400 module_exit(exit_fw)
 401 MODULE_LICENSE("GPL");