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 256
  33
  34 struct fw_head {
  35         u32                     mask;
  36         struct fw_filter __rcu  *ht[HTSIZE];
  37         struct rcu_head         rcu;
  38 };
  39
  40 struct fw_filter {
  41         struct fw_filter __rcu  *next;
  42         u32                     id;
  43         struct tcf_result       res;
  44 #ifdef CONFIG_NET_CLS_IND
  45         int                     ifindex;
  46 #endif /* CONFIG_NET_CLS_IND */
  47         struct tcf_exts         exts;
  48         struct tcf_proto        *tp;
  49         struct rcu_head         rcu;
  50 };
  51
  52 static u32 fw_hash(u32 handle)
  53 {
  54         handle ^= (handle >> 16);
  55         handle ^= (handle >> 8);
  56         return handle % HTSIZE;
  57 }
  58
  59 static int fw_classify(struct sk_buff *skb, const struct tcf_proto *tp,
  60                           struct tcf_result *res)
  61 {
  62         struct fw_head *head = rcu_dereference_bh(tp->root);
  63         struct fw_filter *f;
  64         int r;
  65         u32 id = skb->mark;
  66
  67         if (head != NULL) {
  68                 id &= head->mask;
  69
  70                 for (f = rcu_dereference_bh(head->ht[fw_hash(id)]); f;
  71                      f = rcu_dereference_bh(f->next)) {
  72                         if (f->id == id) {
  73                                 *res = f->res;
  74 #ifdef CONFIG_NET_CLS_IND
  75                                 if (!tcf_match_indev(skb, f->ifindex))
  76                                         continue;
  77 #endif /* CONFIG_NET_CLS_IND */
  78                                 r = tcf_exts_exec(skb, &f->exts, res);
  79                                 if (r < 0)
  80                                         continue;
  81
  82                                 return r;
  83                         }
  84                 }
  85         } else {
  86                 /* old method */
  87                 if (id && (TC_H_MAJ(id) == 0 ||
  88                            !(TC_H_MAJ(id ^ tp->q->handle)))) {
  89                         res->classid = id;
  90                         res->class = 0;
  91                         return 0;
  92                 }
  93         }
  94
  95         return -1;
  96 }
  97
  98 static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
  99 {
 100         struct fw_head *head = rtnl_dereference(tp->root);
 101         struct fw_filter *f;
 102
 103         if (head == NULL)
 104                 return 0;
 105
 106         f = rtnl_dereference(head->ht[fw_hash(handle)]);
 107         for (; f; f = rtnl_dereference(f->next)) {
 108                 if (f->id == handle)
 109                         return (unsigned long)f;
 110         }
 111         return 0;
 112 }
 113
 114 static void fw_put(struct tcf_proto *tp, unsigned long f)
 115 {
 116 }
 117
 118 static int fw_init(struct tcf_proto *tp)
 119 {
 120         return 0;
 121 }
 122
 123 static void fw_delete_filter(struct rcu_head *head)
 124 {
 125         struct fw_filter *f = container_of(head, struct fw_filter, rcu);
 126         struct tcf_proto *tp = f->tp;
 127
 128         tcf_unbind_filter(tp, &f->res);
 129         tcf_exts_destroy(tp, &f->exts);
 130         kfree(f);
 131 }
 132
 133 static void fw_destroy(struct tcf_proto *tp)
 134 {
 135         struct fw_head *head = rtnl_dereference(tp->root);
 136         struct fw_filter *f;
 137         int h;
 138
 139         if (head == NULL)
 140                 return;
 141
 142         for (h = 0; h < HTSIZE; h++) {
 143                 while ((f = rtnl_dereference(head->ht[h])) != NULL) {
 144                         RCU_INIT_POINTER(head->ht[h],
 145                                          rtnl_dereference(f->next));
 146                         call_rcu(&f->rcu, fw_delete_filter);
 147                 }
 148         }
 149         RCU_INIT_POINTER(tp->root, NULL);
 150         kfree_rcu(head, rcu);
 151 }
 152
 153 static int fw_delete(struct tcf_proto *tp, unsigned long arg)
 154 {
 155         struct fw_head *head = rtnl_dereference(tp->root);
 156         struct fw_filter *f = (struct fw_filter *)arg;
 157         struct fw_filter __rcu **fp;
 158         struct fw_filter *pfp;
 159
 160         if (head == NULL || f == NULL)
 161                 goto out;
 162
 163         fp = &head->ht[fw_hash(f->id)];
 164
 165         for (pfp = rtnl_dereference(*fp); pfp;
 166              fp = &pfp->next, pfp = rtnl_dereference(*fp)) {
 167                 if (pfp == f) {
 168                         RCU_INIT_POINTER(*fp, rtnl_dereference(f->next));
 169                         call_rcu(&f->rcu, fw_delete_filter);
 170                         return 0;
 171                 }
 172         }
 173 out:
 174         return -EINVAL;
 175 }
 176
 177 static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
 178         [TCA_FW_CLASSID]        = { .type = NLA_U32 },
 179         [TCA_FW_INDEV]          = { .type = NLA_STRING, .len = IFNAMSIZ },
 180         [TCA_FW_MASK]           = { .type = NLA_U32 },
 181 };
 182
 183 static int
 184 fw_change_attrs(struct net *net, struct tcf_proto *tp, struct fw_filter *f,
 185         struct nlattr **tb, struct nlattr **tca, unsigned long base, bool ovr)
 186 {
 187         struct fw_head *head = rtnl_dereference(tp->root);
 188         struct tcf_exts e;
 189         u32 mask;
 190         int err;
 191
 192         tcf_exts_init(&e, TCA_FW_ACT, TCA_FW_POLICE);
 193         err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr);
 194         if (err < 0)
 195                 return err;
 196
 197         if (tb[TCA_FW_CLASSID]) {
 198                 f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
 199                 tcf_bind_filter(tp, &f->res, base);
 200         }
 201
 202 #ifdef CONFIG_NET_CLS_IND
 203         if (tb[TCA_FW_INDEV]) {
 204                 int ret;
 205                 ret = tcf_change_indev(net, tb[TCA_FW_INDEV]);
 206                 if (ret < 0) {
 207                         err = ret;
 208                         goto errout;
 209                 }
 210                 f->ifindex = ret;
 211         }
 212 #endif /* CONFIG_NET_CLS_IND */
 213
 214         err = -EINVAL;
 215         if (tb[TCA_FW_MASK]) {
 216                 mask = nla_get_u32(tb[TCA_FW_MASK]);
 217                 if (mask != head->mask)
 218                         goto errout;
 219         } else if (head->mask != 0xFFFFFFFF)
 220                 goto errout;
 221
 222         tcf_exts_change(tp, &f->exts, &e);
 223
 224         return 0;
 225 errout:
 226         tcf_exts_destroy(tp, &e);
 227         return err;
 228 }
 229
 230 static int fw_change(struct net *net, struct sk_buff *in_skb,
 231                      struct tcf_proto *tp, unsigned long base,
 232                      u32 handle,
 233                      struct nlattr **tca,
 234                      unsigned long *arg, bool ovr)
 235 {
 236         struct fw_head *head = rtnl_dereference(tp->root);
 237         struct fw_filter *f = (struct fw_filter *) *arg;
 238         struct nlattr *opt = tca[TCA_OPTIONS];
 239         struct nlattr *tb[TCA_FW_MAX + 1];
 240         int err;
 241
 242         if (!opt)
 243                 return handle ? -EINVAL : 0;
 244
 245         err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
 246         if (err < 0)
 247                 return err;
 248
 249         if (f) {
 250                 struct fw_filter *pfp, *fnew;
 251                 struct fw_filter __rcu **fp;
 252
 253                 if (f->id != handle && handle)
 254                         return -EINVAL;
 255
 256                 fnew = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
 257                 if (!fnew)
 258                         return -ENOBUFS;
 259
 260                 fnew->id = f->id;
 261                 fnew->res = f->res;
 262 #ifdef CONFIG_NET_CLS_IND
 263                 fnew->ifindex = f->ifindex;
 264 #endif /* CONFIG_NET_CLS_IND */
 265                 fnew->tp = f->tp;
 266
 267                 tcf_exts_init(&fnew->exts, TCA_FW_ACT, TCA_FW_POLICE);
 268
 269                 err = fw_change_attrs(net, tp, fnew, tb, tca, base, ovr);
 270                 if (err < 0) {
 271                         kfree(fnew);
 272                         return err;
 273                 }
 274
 275                 fp = &head->ht[fw_hash(fnew->id)];
 276                 for (pfp = rtnl_dereference(*fp); pfp;
 277                      fp = &pfp->next, pfp = rtnl_dereference(*fp))
 278                         if (pfp == f)
 279                                 break;
 280
 281                 RCU_INIT_POINTER(fnew->next, rtnl_dereference(pfp->next));
 282                 rcu_assign_pointer(*fp, fnew);
 283                 call_rcu(&f->rcu, fw_delete_filter);
 284
 285                 *arg = (unsigned long)fnew;
 286                 return err;
 287         }
 288
 289         if (!handle)
 290                 return -EINVAL;
 291
 292         if (head == NULL) {
 293                 u32 mask = 0xFFFFFFFF;
 294                 if (tb[TCA_FW_MASK])
 295                         mask = nla_get_u32(tb[TCA_FW_MASK]);
 296
 297                 head = kzalloc(sizeof(struct fw_head), GFP_KERNEL);
 298                 if (head == NULL)
 299                         return -ENOBUFS;
 300                 head->mask = mask;
 301
 302                 rcu_assign_pointer(tp->root, head);
 303         }
 304
 305         f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
 306         if (f == NULL)
 307                 return -ENOBUFS;
 308
 309         tcf_exts_init(&f->exts, TCA_FW_ACT, TCA_FW_POLICE);
 310         f->id = handle;
 311         f->tp = tp;
 312
 313         err = fw_change_attrs(net, tp, f, tb, tca, base, ovr);
 314         if (err < 0)
 315                 goto errout;
 316
 317         RCU_INIT_POINTER(f->next, head->ht[fw_hash(handle)]);
 318         rcu_assign_pointer(head->ht[fw_hash(handle)], f);
 319
 320         *arg = (unsigned long)f;
 321         return 0;
 322
 323 errout:
 324         kfree(f);
 325         return err;
 326 }
 327
 328 static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 329 {
 330         struct fw_head *head = rtnl_dereference(tp->root);
 331         int h;
 332
 333         if (head == NULL)
 334                 arg->stop = 1;
 335
 336         if (arg->stop)
 337                 return;
 338
 339         for (h = 0; h < HTSIZE; h++) {
 340                 struct fw_filter *f;
 341
 342                 for (f = rtnl_dereference(head->ht[h]); f;
 343                      f = rtnl_dereference(f->next)) {
 344                         if (arg->count < arg->skip) {
 345                                 arg->count++;
 346                                 continue;
 347                         }
 348                         if (arg->fn(tp, (unsigned long)f, arg) < 0) {
 349                                 arg->stop = 1;
 350                                 return;
 351                         }
 352                         arg->count++;
 353                 }
 354         }
 355 }
 356
 357 static int fw_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
 358                    struct sk_buff *skb, struct tcmsg *t)
 359 {
 360         struct fw_head *head = rtnl_dereference(tp->root);
 361         struct fw_filter *f = (struct fw_filter *)fh;
 362         unsigned char *b = skb_tail_pointer(skb);
 363         struct nlattr *nest;
 364
 365         if (f == NULL)
 366                 return skb->len;
 367
 368         t->tcm_handle = f->id;
 369
 370         if (!f->res.classid && !tcf_exts_is_available(&f->exts))
 371                 return skb->len;
 372
 373         nest = nla_nest_start(skb, TCA_OPTIONS);
 374         if (nest == NULL)
 375                 goto nla_put_failure;
 376
 377         if (f->res.classid &&
 378             nla_put_u32(skb, TCA_FW_CLASSID, f->res.classid))
 379                 goto nla_put_failure;
 380 #ifdef CONFIG_NET_CLS_IND
 381         if (f->ifindex) {
 382                 struct net_device *dev;
 383                 dev = __dev_get_by_index(net, f->ifindex);
 384                 if (dev && nla_put_string(skb, TCA_FW_INDEV, dev->name))
 385                         goto nla_put_failure;
 386         }
 387 #endif /* CONFIG_NET_CLS_IND */
 388         if (head->mask != 0xFFFFFFFF &&
 389             nla_put_u32(skb, TCA_FW_MASK, head->mask))
 390                 goto nla_put_failure;
 391
 392         if (tcf_exts_dump(skb, &f->exts) < 0)
 393                 goto nla_put_failure;
 394
 395         nla_nest_end(skb, nest);
 396
 397         if (tcf_exts_dump_stats(skb, &f->exts) < 0)
 398                 goto nla_put_failure;
 399
 400         return skb->len;
 401
 402 nla_put_failure:
 403         nlmsg_trim(skb, b);
 404         return -1;
 405 }
 406
 407 static struct tcf_proto_ops cls_fw_ops __read_mostly = {
 408         .kind           =       "fw",
 409         .classify       =       fw_classify,
 410         .init           =       fw_init,
 411         .destroy        =       fw_destroy,
 412         .get            =       fw_get,
 413         .put            =       fw_put,
 414         .change         =       fw_change,
 415         .delete         =       fw_delete,
 416         .walk           =       fw_walk,
 417         .dump           =       fw_dump,
 418         .owner          =       THIS_MODULE,
 419 };
 420
 421 static int __init init_fw(void)
 422 {
 423         return register_tcf_proto_ops(&cls_fw_ops);
 424 }
 425
 426 static void __exit exit_fw(void)
 427 {
 428         unregister_tcf_proto_ops(&cls_fw_ops);
 429 }
 430
 431 module_init(init_fw)
 432 module_exit(exit_fw)
 433 MODULE_LICENSE("GPL");