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         bool                    mask_set;
  37         struct fw_filter __rcu  *ht[HTSIZE];
  38         struct rcu_head         rcu;
  39 };
  40
  41 struct fw_filter {
  42         struct fw_filter __rcu  *next;
  43         u32                     id;
  44         struct tcf_result       res;
  45 #ifdef CONFIG_NET_CLS_IND
  46         int                     ifindex;
  47 #endif /* CONFIG_NET_CLS_IND */
  48         struct tcf_exts         exts;
  49         struct tcf_proto        *tp;
  50         struct rcu_head         rcu;
  51 };
  52
  53 static u32 fw_hash(u32 handle)
  54 {
  55         handle ^= (handle >> 16);
  56         handle ^= (handle >> 8);
  57         return handle % HTSIZE;
  58 }
  59
  60 static int fw_classify(struct sk_buff *skb, const struct tcf_proto *tp,
  61                           struct tcf_result *res)
  62 {
  63         struct fw_head *head = rcu_dereference_bh(tp->root);
  64         struct fw_filter *f;
  65         int r;
  66         u32 id = skb->mark;
  67
  68         if (head != NULL) {
  69                 id &= head->mask;
  70
  71                 for (f = rcu_dereference_bh(head->ht[fw_hash(id)]); f;
  72                      f = rcu_dereference_bh(f->next)) {
  73                         if (f->id == id) {
  74                                 *res = f->res;
  75 #ifdef CONFIG_NET_CLS_IND
  76                                 if (!tcf_match_indev(skb, f->ifindex))
  77                                         continue;
  78 #endif /* CONFIG_NET_CLS_IND */
  79                                 r = tcf_exts_exec(skb, &f->exts, res);
  80                                 if (r < 0)
  81                                         continue;
  82
  83                                 return r;
  84                         }
  85                 }
  86         } else {
  87                 /* old method */
  88                 if (id && (TC_H_MAJ(id) == 0 ||
  89                            !(TC_H_MAJ(id ^ tp->q->handle)))) {
  90                         res->classid = id;
  91                         res->class = 0;
  92                         return 0;
  93                 }
  94         }
  95
  96         return -1;
  97 }
  98
  99 static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
 100 {
 101         struct fw_head *head = rtnl_dereference(tp->root);
 102         struct fw_filter *f;
 103
 104         if (head == NULL)
 105                 return 0;
 106
 107         f = rtnl_dereference(head->ht[fw_hash(handle)]);
 108         for (; f; f = rtnl_dereference(f->next)) {
 109                 if (f->id == handle)
 110                         return (unsigned long)f;
 111         }
 112         return 0;
 113 }
 114
 115 static int fw_init(struct tcf_proto *tp)
 116 {
 117         struct fw_head *head;
 118
 119         head = kzalloc(sizeof(struct fw_head), GFP_KERNEL);
 120         if (head == NULL)
 121                 return -ENOBUFS;
 122
 123         head->mask_set = false;
 124         rcu_assign_pointer(tp->root, head);
 125         return 0;
 126 }
 127
 128 static void fw_delete_filter(struct rcu_head *head)
 129 {
 130         struct fw_filter *f = container_of(head, struct fw_filter, rcu);
 131
 132         tcf_exts_destroy(&f->exts);
 133         kfree(f);
 134 }
 135
 136 static bool fw_destroy(struct tcf_proto *tp, bool force)
 137 {
 138         struct fw_head *head = rtnl_dereference(tp->root);
 139         struct fw_filter *f;
 140         int h;
 141
 142         if (head == NULL)
 143                 return true;
 144
 145         if (!force) {
 146                 for (h = 0; h < HTSIZE; h++)
 147                         if (rcu_access_pointer(head->ht[h]))
 148                                 return false;
 149         }
 150
 151         for (h = 0; h < HTSIZE; h++) {
 152                 while ((f = rtnl_dereference(head->ht[h])) != NULL) {
 153                         RCU_INIT_POINTER(head->ht[h],
 154                                          rtnl_dereference(f->next));
 155                         tcf_unbind_filter(tp, &f->res);
 156                         call_rcu(&f->rcu, fw_delete_filter);
 157                 }
 158         }
 159         RCU_INIT_POINTER(tp->root, NULL);
 160         kfree_rcu(head, rcu);
 161         return true;
 162 }
 163
 164 static int fw_delete(struct tcf_proto *tp, unsigned long arg)
 165 {
 166         struct fw_head *head = rtnl_dereference(tp->root);
 167         struct fw_filter *f = (struct fw_filter *)arg;
 168         struct fw_filter __rcu **fp;
 169         struct fw_filter *pfp;
 170
 171         if (head == NULL || f == NULL)
 172                 goto out;
 173
 174         fp = &head->ht[fw_hash(f->id)];
 175
 176         for (pfp = rtnl_dereference(*fp); pfp;
 177              fp = &pfp->next, pfp = rtnl_dereference(*fp)) {
 178                 if (pfp == f) {
 179                         RCU_INIT_POINTER(*fp, rtnl_dereference(f->next));
 180                         tcf_unbind_filter(tp, &f->res);
 181                         call_rcu(&f->rcu, fw_delete_filter);
 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 net *net, struct tcf_proto *tp, struct fw_filter *f,
 197         struct nlattr **tb, struct nlattr **tca, unsigned long base, bool ovr)
 198 {
 199         struct fw_head *head = rtnl_dereference(tp->root);
 200         struct tcf_exts e;
 201         u32 mask;
 202         int err;
 203
 204         tcf_exts_init(&e, TCA_FW_ACT, TCA_FW_POLICE);
 205         err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr);
 206         if (err < 0)
 207                 return err;
 208
 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                 int ret;
 217                 ret = tcf_change_indev(net, tb[TCA_FW_INDEV]);
 218                 if (ret < 0) {
 219                         err = ret;
 220                         goto errout;
 221                 }
 222                 f->ifindex = ret;
 223         }
 224 #endif /* CONFIG_NET_CLS_IND */
 225
 226         err = -EINVAL;
 227         if (tb[TCA_FW_MASK]) {
 228                 mask = nla_get_u32(tb[TCA_FW_MASK]);
 229                 if (mask != head->mask)
 230                         goto errout;
 231         } else if (head->mask != 0xFFFFFFFF)
 232                 goto errout;
 233
 234         tcf_exts_change(tp, &f->exts, &e);
 235
 236         return 0;
 237 errout:
 238         tcf_exts_destroy(&e);
 239         return err;
 240 }
 241
 242 static int fw_change(struct net *net, struct sk_buff *in_skb,
 243                      struct tcf_proto *tp, unsigned long base,
 244                      u32 handle,
 245                      struct nlattr **tca,
 246                      unsigned long *arg, bool ovr)
 247 {
 248         struct fw_head *head = rtnl_dereference(tp->root);
 249         struct fw_filter *f = (struct fw_filter *) *arg;
 250         struct nlattr *opt = tca[TCA_OPTIONS];
 251         struct nlattr *tb[TCA_FW_MAX + 1];
 252         int err;
 253
 254         if (!opt)
 255                 return handle ? -EINVAL : 0;
 256
 257         err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
 258         if (err < 0)
 259                 return err;
 260
 261         if (f) {
 262                 struct fw_filter *pfp, *fnew;
 263                 struct fw_filter __rcu **fp;
 264
 265                 if (f->id != handle && handle)
 266                         return -EINVAL;
 267
 268                 fnew = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
 269                 if (!fnew)
 270                         return -ENOBUFS;
 271
 272                 fnew->id = f->id;
 273                 fnew->res = f->res;
 274 #ifdef CONFIG_NET_CLS_IND
 275                 fnew->ifindex = f->ifindex;
 276 #endif /* CONFIG_NET_CLS_IND */
 277                 fnew->tp = f->tp;
 278
 279                 tcf_exts_init(&fnew->exts, TCA_FW_ACT, TCA_FW_POLICE);
 280
 281                 err = fw_change_attrs(net, tp, fnew, tb, tca, base, ovr);
 282                 if (err < 0) {
 283                         kfree(fnew);
 284                         return err;
 285                 }
 286
 287                 fp = &head->ht[fw_hash(fnew->id)];
 288                 for (pfp = rtnl_dereference(*fp); pfp;
 289                      fp = &pfp->next, pfp = rtnl_dereference(*fp))
 290                         if (pfp == f)
 291                                 break;
 292
 293                 RCU_INIT_POINTER(fnew->next, rtnl_dereference(pfp->next));
 294                 rcu_assign_pointer(*fp, fnew);
 295                 tcf_unbind_filter(tp, &f->res);
 296                 call_rcu(&f->rcu, fw_delete_filter);
 297
 298                 *arg = (unsigned long)fnew;
 299                 return err;
 300         }
 301
 302         if (!handle)
 303                 return -EINVAL;
 304
 305         if (!head->mask_set) {
 306                 head->mask = 0xFFFFFFFF;
 307                 if (tb[TCA_FW_MASK])
 308                         head->mask = nla_get_u32(tb[TCA_FW_MASK]);
 309                 head->mask_set = true;
 310         }
 311
 312         f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
 313         if (f == NULL)
 314                 return -ENOBUFS;
 315
 316         tcf_exts_init(&f->exts, TCA_FW_ACT, TCA_FW_POLICE);
 317         f->id = handle;
 318         f->tp = tp;
 319
 320         err = fw_change_attrs(net, tp, f, tb, tca, base, ovr);
 321         if (err < 0)
 322                 goto errout;
 323
 324         RCU_INIT_POINTER(f->next, head->ht[fw_hash(handle)]);
 325         rcu_assign_pointer(head->ht[fw_hash(handle)], f);
 326
 327         *arg = (unsigned long)f;
 328         return 0;
 329
 330 errout:
 331         kfree(f);
 332         return err;
 333 }
 334
 335 static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 336 {
 337         struct fw_head *head = rtnl_dereference(tp->root);
 338         int h;
 339
 340         if (head == NULL)
 341                 arg->stop = 1;
 342
 343         if (arg->stop)
 344                 return;
 345
 346         for (h = 0; h < HTSIZE; h++) {
 347                 struct fw_filter *f;
 348
 349                 for (f = rtnl_dereference(head->ht[h]); f;
 350                      f = rtnl_dereference(f->next)) {
 351                         if (arg->count < arg->skip) {
 352                                 arg->count++;
 353                                 continue;
 354                         }
 355                         if (arg->fn(tp, (unsigned long)f, arg) < 0) {
 356                                 arg->stop = 1;
 357                                 return;
 358                         }
 359                         arg->count++;
 360                 }
 361         }
 362 }
 363
 364 static int fw_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
 365                    struct sk_buff *skb, struct tcmsg *t)
 366 {
 367         struct fw_head *head = rtnl_dereference(tp->root);
 368         struct fw_filter *f = (struct fw_filter *)fh;
 369         struct nlattr *nest;
 370
 371         if (f == NULL)
 372                 return skb->len;
 373
 374         t->tcm_handle = f->id;
 375
 376         if (!f->res.classid && !tcf_exts_is_available(&f->exts))
 377                 return skb->len;
 378
 379         nest = nla_nest_start(skb, TCA_OPTIONS);
 380         if (nest == NULL)
 381                 goto nla_put_failure;
 382
 383         if (f->res.classid &&
 384             nla_put_u32(skb, TCA_FW_CLASSID, f->res.classid))
 385                 goto nla_put_failure;
 386 #ifdef CONFIG_NET_CLS_IND
 387         if (f->ifindex) {
 388                 struct net_device *dev;
 389                 dev = __dev_get_by_index(net, f->ifindex);
 390                 if (dev && nla_put_string(skb, TCA_FW_INDEV, dev->name))
 391                         goto nla_put_failure;
 392         }
 393 #endif /* CONFIG_NET_CLS_IND */
 394         if (head->mask != 0xFFFFFFFF &&
 395             nla_put_u32(skb, TCA_FW_MASK, head->mask))
 396                 goto nla_put_failure;
 397
 398         if (tcf_exts_dump(skb, &f->exts) < 0)
 399                 goto nla_put_failure;
 400
 401         nla_nest_end(skb, nest);
 402
 403         if (tcf_exts_dump_stats(skb, &f->exts) < 0)
 404                 goto nla_put_failure;
 405
 406         return skb->len;
 407
 408 nla_put_failure:
 409         nla_nest_cancel(skb, nest);
 410         return -1;
 411 }
 412
 413 static struct tcf_proto_ops cls_fw_ops __read_mostly = {
 414         .kind           =       "fw",
 415         .classify       =       fw_classify,
 416         .init           =       fw_init,
 417         .destroy        =       fw_destroy,
 418         .get            =       fw_get,
 419         .change         =       fw_change,
 420         .delete         =       fw_delete,
 421         .walk           =       fw_walk,
 422         .dump           =       fw_dump,
 423         .owner          =       THIS_MODULE,
 424 };
 425
 426 static int __init init_fw(void)
 427 {
 428         return register_tcf_proto_ops(&cls_fw_ops);
 429 }
 430
 431 static void __exit exit_fw(void)
 432 {
 433         unregister_tcf_proto_ops(&cls_fw_ops);
 434 }
 435
 436 module_init(init_fw)
 437 module_exit(exit_fw)
 438 MODULE_LICENSE("GPL");