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         struct fw_filter *ht[HTSIZE];
  36         u32 mask;
  37 };
  38
  39 struct 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
  49 static const struct tcf_ext_map fw_ext_map = {
  50         .action = TCA_FW_ACT,
  51         .police = TCA_FW_POLICE
  52 };
  53
  54 static 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
  80 static 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
 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 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
 148 static 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
 166 static 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         }
 184 out:
 185         return -EINVAL;
 186 }
 187
 188 static 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
 194 static int
 195 fw_change_attrs(struct net *net, 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(net, tp, tb, tca[TCA_RATE], &e, &fw_ext_map);
 204         if (err < 0)
 205                 return err;
 206
 207         if (tb[TCA_FW_CLASSID]) {
 208                 f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
 209                 tcf_bind_filter(tp, &f->res, base);
 210         }
 211
 212 #ifdef CONFIG_NET_CLS_IND
 213         if (tb[TCA_FW_INDEV]) {
 214                 err = tcf_change_indev(tp, f->indev, tb[TCA_FW_INDEV]);
 215                 if (err < 0)
 216                         goto errout;
 217         }
 218 #endif /* CONFIG_NET_CLS_IND */
 219
 220         err = -EINVAL;
 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;
 231 errout:
 232         tcf_exts_destroy(tp, &e);
 233         return err;
 234 }
 235
 236 static int fw_change(struct net *net, struct sk_buff *in_skb,
 237                      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(net, 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         tcf_exts_init(&f->exts);
 284         f->id = handle;
 285
 286         err = fw_change_attrs(net, 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                 goto nla_put_failure;
 354 #ifdef CONFIG_NET_CLS_IND
 355         if (strlen(f->indev) &&
 356             nla_put_string(skb, TCA_FW_INDEV, f->indev))
 357                 goto nla_put_failure;
 358 #endif /* CONFIG_NET_CLS_IND */
 359         if (head->mask != 0xFFFFFFFF &&
 360             nla_put_u32(skb, TCA_FW_MASK, head->mask))
 361                 goto nla_put_failure;
 362
 363         if (tcf_exts_dump(skb, &f->exts, &fw_ext_map) < 0)
 364                 goto nla_put_failure;
 365
 366         nla_nest_end(skb, nest);
 367
 368         if (tcf_exts_dump_stats(skb, &f->exts, &fw_ext_map) < 0)
 369                 goto nla_put_failure;
 370
 371         return skb->len;
 372
 373 nla_put_failure:
 374         nlmsg_trim(skb, b);
 375         return -1;
 376 }
 377
 378 static struct tcf_proto_ops cls_fw_ops __read_mostly = {
 379         .kind           =       "fw",
 380         .classify       =       fw_classify,
 381         .init           =       fw_init,
 382         .destroy        =       fw_destroy,
 383         .get            =       fw_get,
 384         .put            =       fw_put,
 385         .change         =       fw_change,
 386         .delete         =       fw_delete,
 387         .walk           =       fw_walk,
 388         .dump           =       fw_dump,
 389         .owner          =       THIS_MODULE,
 390 };
 391
 392 static int __init init_fw(void)
 393 {
 394         return register_tcf_proto_ops(&cls_fw_ops);
 395 }
 396
 397 static void __exit exit_fw(void)
 398 {
 399         unregister_tcf_proto_ops(&cls_fw_ops);
 400 }
 401
 402 module_init(init_fw)
 403 module_exit(exit_fw)
 404 MODULE_LICENSE("GPL");