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