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         int                     ifindex;
  45 #endif /* CONFIG_NET_CLS_IND */
  46         struct tcf_exts         exts;
  47 };
  48
  49 static inline int fw_hash(u32 handle)
  50 {
  51         if (HTSIZE == 4096)
  52                 return ((handle >> 24) & 0xFFF) ^
  53                        ((handle >> 12) & 0xFFF) ^
  54                        (handle & 0xFFF);
  55         else if (HTSIZE == 2048)
  56                 return ((handle >> 22) & 0x7FF) ^
  57                        ((handle >> 11) & 0x7FF) ^
  58                        (handle & 0x7FF);
  59         else if (HTSIZE == 1024)
  60                 return ((handle >> 20) & 0x3FF) ^
  61                        ((handle >> 10) & 0x3FF) ^
  62                        (handle & 0x3FF);
  63         else if (HTSIZE == 512)
  64                 return (handle >> 27) ^
  65                        ((handle >> 18) & 0x1FF) ^
  66                        ((handle >> 9) & 0x1FF) ^
  67                        (handle & 0x1FF);
  68         else if (HTSIZE == 256) {
  69                 u8 *t = (u8 *) &handle;
  70                 return t[0] ^ t[1] ^ t[2] ^ t[3];
  71         } else
  72                 return handle & (HTSIZE - 1);
  73 }
  74
  75 static int fw_classify(struct sk_buff *skb, const struct tcf_proto *tp,
  76                           struct tcf_result *res)
  77 {
  78         struct fw_head *head = tp->root;
  79         struct fw_filter *f;
  80         int r;
  81         u32 id = skb->mark;
  82
  83         if (head != NULL) {
  84                 id &= head->mask;
  85                 for (f = head->ht[fw_hash(id)]; f; f = f->next) {
  86                         if (f->id == id) {
  87                                 *res = f->res;
  88 #ifdef CONFIG_NET_CLS_IND
  89                                 if (!tcf_match_indev(skb, f->ifindex))
  90                                         continue;
  91 #endif /* CONFIG_NET_CLS_IND */
  92                                 r = tcf_exts_exec(skb, &f->exts, res);
  93                                 if (r < 0)
  94                                         continue;
  95
  96                                 return r;
  97                         }
  98                 }
  99         } else {
 100                 /* old method */
 101                 if (id && (TC_H_MAJ(id) == 0 ||
 102                            !(TC_H_MAJ(id ^ tp->q->handle)))) {
 103                         res->classid = id;
 104                         res->class = 0;
 105                         return 0;
 106                 }
 107         }
 108
 109         return -1;
 110 }
 111
 112 static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
 113 {
 114         struct fw_head *head = tp->root;
 115         struct fw_filter *f;
 116
 117         if (head == NULL)
 118                 return 0;
 119
 120         for (f = head->ht[fw_hash(handle)]; f; f = f->next) {
 121                 if (f->id == handle)
 122                         return (unsigned long)f;
 123         }
 124         return 0;
 125 }
 126
 127 static void fw_put(struct tcf_proto *tp, unsigned long f)
 128 {
 129 }
 130
 131 static int fw_init(struct tcf_proto *tp)
 132 {
 133         return 0;
 134 }
 135
 136 static void fw_delete_filter(struct tcf_proto *tp, struct fw_filter *f)
 137 {
 138         tcf_unbind_filter(tp, &f->res);
 139         tcf_exts_destroy(tp, &f->exts);
 140         kfree(f);
 141 }
 142
 143 static void fw_destroy(struct tcf_proto *tp)
 144 {
 145         struct fw_head *head = tp->root;
 146         struct fw_filter *f;
 147         int h;
 148
 149         if (head == NULL)
 150                 return;
 151
 152         for (h = 0; h < HTSIZE; h++) {
 153                 while ((f = head->ht[h]) != NULL) {
 154                         head->ht[h] = f->next;
 155                         fw_delete_filter(tp, f);
 156                 }
 157         }
 158         kfree(head);
 159 }
 160
 161 static int fw_delete(struct tcf_proto *tp, unsigned long arg)
 162 {
 163         struct fw_head *head = tp->root;
 164         struct fw_filter *f = (struct fw_filter *)arg;
 165         struct fw_filter **fp;
 166
 167         if (head == NULL || f == NULL)
 168                 goto out;
 169
 170         for (fp = &head->ht[fw_hash(f->id)]; *fp; fp = &(*fp)->next) {
 171                 if (*fp == f) {
 172                         tcf_tree_lock(tp);
 173                         *fp = f->next;
 174                         tcf_tree_unlock(tp);
 175                         fw_delete_filter(tp, f);
 176                         return 0;
 177                 }
 178         }
 179 out:
 180         return -EINVAL;
 181 }
 182
 183 static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
 184         [TCA_FW_CLASSID]        = { .type = NLA_U32 },
 185         [TCA_FW_INDEV]          = { .type = NLA_STRING, .len = IFNAMSIZ },
 186         [TCA_FW_MASK]           = { .type = NLA_U32 },
 187 };
 188
 189 static int
 190 fw_change_attrs(struct net *net, struct tcf_proto *tp, struct fw_filter *f,
 191         struct nlattr **tb, struct nlattr **tca, unsigned long base)
 192 {
 193         struct fw_head *head = tp->root;
 194         struct tcf_exts e;
 195         u32 mask;
 196         int err;
 197
 198         tcf_exts_init(&e, TCA_FW_ACT, TCA_FW_POLICE);
 199         err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e);
 200         if (err < 0)
 201                 return err;
 202
 203         if (tb[TCA_FW_CLASSID]) {
 204                 f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
 205                 tcf_bind_filter(tp, &f->res, base);
 206         }
 207
 208 #ifdef CONFIG_NET_CLS_IND
 209         if (tb[TCA_FW_INDEV]) {
 210                 int ret;
 211                 ret = tcf_change_indev(net, tb[TCA_FW_INDEV]);
 212                 if (ret < 0)
 213                         goto errout;
 214                 f->ifindex = ret;
 215         }
 216 #endif /* CONFIG_NET_CLS_IND */
 217
 218         err = -EINVAL;
 219         if (tb[TCA_FW_MASK]) {
 220                 mask = nla_get_u32(tb[TCA_FW_MASK]);
 221                 if (mask != head->mask)
 222                         goto errout;
 223         } else if (head->mask != 0xFFFFFFFF)
 224                 goto errout;
 225
 226         tcf_exts_change(tp, &f->exts, &e);
 227
 228         return 0;
 229 errout:
 230         tcf_exts_destroy(tp, &e);
 231         return err;
 232 }
 233
 234 static int fw_change(struct net *net, struct sk_buff *in_skb,
 235                      struct tcf_proto *tp, unsigned long base,
 236                      u32 handle,
 237                      struct nlattr **tca,
 238                      unsigned long *arg)
 239 {
 240         struct fw_head *head = tp->root;
 241         struct fw_filter *f = (struct fw_filter *) *arg;
 242         struct nlattr *opt = tca[TCA_OPTIONS];
 243         struct nlattr *tb[TCA_FW_MAX + 1];
 244         int err;
 245
 246         if (!opt)
 247                 return handle ? -EINVAL : 0;
 248
 249         err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
 250         if (err < 0)
 251                 return err;
 252
 253         if (f != NULL) {
 254                 if (f->id != handle && handle)
 255                         return -EINVAL;
 256                 return fw_change_attrs(net, tp, f, tb, tca, base);
 257         }
 258
 259         if (!handle)
 260                 return -EINVAL;
 261
 262         if (head == NULL) {
 263                 u32 mask = 0xFFFFFFFF;
 264                 if (tb[TCA_FW_MASK])
 265                         mask = nla_get_u32(tb[TCA_FW_MASK]);
 266
 267                 head = kzalloc(sizeof(struct fw_head), GFP_KERNEL);
 268                 if (head == NULL)
 269                         return -ENOBUFS;
 270                 head->mask = mask;
 271
 272                 tcf_tree_lock(tp);
 273                 tp->root = head;
 274                 tcf_tree_unlock(tp);
 275         }
 276
 277         f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
 278         if (f == NULL)
 279                 return -ENOBUFS;
 280
 281         tcf_exts_init(&f->exts, TCA_FW_ACT, TCA_FW_POLICE);
 282         f->id = handle;
 283
 284         err = fw_change_attrs(net, 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
 296 errout:
 297         kfree(f);
 298         return err;
 299 }
 300
 301 static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 302 {
 303         struct fw_head *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
 329 static int fw_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
 330                    struct sk_buff *skb, struct tcmsg *t)
 331 {
 332         struct fw_head *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 (f->ifindex) {
 354                 struct net_device *dev;
 355                 dev = __dev_get_by_index(net, f->ifindex);
 356                 if (dev && nla_put_string(skb, TCA_FW_INDEV, dev->name))
 357                         goto nla_put_failure;
 358         }
 359 #endif /* CONFIG_NET_CLS_IND */
 360         if (head->mask != 0xFFFFFFFF &&
 361             nla_put_u32(skb, TCA_FW_MASK, head->mask))
 362                 goto nla_put_failure;
 363
 364         if (tcf_exts_dump(skb, &f->exts) < 0)
 365                 goto nla_put_failure;
 366
 367         nla_nest_end(skb, nest);
 368
 369         if (tcf_exts_dump_stats(skb, &f->exts) < 0)
 370                 goto nla_put_failure;
 371
 372         return skb->len;
 373
 374 nla_put_failure:
 375         nlmsg_trim(skb, b);
 376         return -1;
 377 }
 378
 379 static struct tcf_proto_ops cls_fw_ops __read_mostly = {
 380         .kind           =       "fw",
 381         .classify       =       fw_classify,
 382         .init           =       fw_init,
 383         .destroy        =       fw_destroy,
 384         .get            =       fw_get,
 385         .put            =       fw_put,
 386         .change         =       fw_change,
 387         .delete         =       fw_delete,
 388         .walk           =       fw_walk,
 389         .dump           =       fw_dump,
 390         .owner          =       THIS_MODULE,
 391 };
 392
 393 static int __init init_fw(void)
 394 {
 395         return register_tcf_proto_ops(&cls_fw_ops);
 396 }
 397
 398 static void __exit exit_fw(void)
 399 {
 400         unregister_tcf_proto_ops(&cls_fw_ops);
 401 }
 402
 403 module_init(init_fw)
 404 module_exit(exit_fw)
 405 MODULE_LICENSE("GPL");