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