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/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
  33 struct fw_head
  34 {
  35         struct fw_filter *ht[HTSIZE];
  36         u32 mask;
  37 };
  38
  39 struct 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
  50 static const struct tcf_ext_map fw_ext_map = {
  51         .action = TCA_FW_ACT,
  52         .police = TCA_FW_POLICE
  53 };
  54
  55 static __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
  81 static 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
 117 static 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
 132 static void fw_put(struct tcf_proto *tp, unsigned long f)
 133 {
 134 }
 135
 136 static int fw_init(struct tcf_proto *tp)
 137 {
 138         return 0;
 139 }
 140
 141 static inline void
 142 fw_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
 149 static void fw_destroy(struct tcf_proto *tp)
 150 {
 151         struct fw_head *head = (struct fw_head*)xchg(&tp->root, NULL);
 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
 167 static 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         }
 185 out:
 186         return -EINVAL;
 187 }
 188
 189 static 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
 195 static int
 196 fw_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;
 232 errout:
 233         tcf_exts_destroy(tp, &e);
 234         return err;
 235 }
 236
 237 static 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
 297 errout:
 298         kfree(f);
 299         return err;
 300 }
 301
 302 static 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
 330 static 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
 369 nla_put_failure:
 370         nlmsg_trim(skb, b);
 371         return -1;
 372 }
 373
 374 static 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
 388 static int __init init_fw(void)
 389 {
 390         return register_tcf_proto_ops(&cls_fw_ops);
 391 }
 392
 393 static void __exit exit_fw(void)
 394 {
 395         unregister_tcf_proto_ops(&cls_fw_ops);
 396 }
 397
 398 module_init(init_fw)
 399 module_exit(exit_fw)
 400 MODULE_LICENSE("GPL");