linux/net/sched/cls_basic.c
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   1/*
   2 * net/sched/cls_basic.c        Basic Packet Classifier.
   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:     Thomas Graf <tgraf@suug.ch>
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/slab.h>
  14#include <linux/types.h>
  15#include <linux/kernel.h>
  16#include <linux/string.h>
  17#include <linux/errno.h>
  18#include <linux/rtnetlink.h>
  19#include <linux/skbuff.h>
  20#include <net/netlink.h>
  21#include <net/act_api.h>
  22#include <net/pkt_cls.h>
  23
  24struct basic_head
  25{
  26        u32                     hgenerator;
  27        struct list_head        flist;
  28};
  29
  30struct basic_filter
  31{
  32        u32                     handle;
  33        struct tcf_exts         exts;
  34        struct tcf_ematch_tree  ematches;
  35        struct tcf_result       res;
  36        struct list_head        link;
  37};
  38
  39static const struct tcf_ext_map basic_ext_map = {
  40        .action = TCA_BASIC_ACT,
  41        .police = TCA_BASIC_POLICE
  42};
  43
  44static int basic_classify(struct sk_buff *skb, struct tcf_proto *tp,
  45                          struct tcf_result *res)
  46{
  47        int r;
  48        struct basic_head *head = (struct basic_head *) tp->root;
  49        struct basic_filter *f;
  50
  51        list_for_each_entry(f, &head->flist, link) {
  52                if (!tcf_em_tree_match(skb, &f->ematches, NULL))
  53                        continue;
  54                *res = f->res;
  55                r = tcf_exts_exec(skb, &f->exts, res);
  56                if (r < 0)
  57                        continue;
  58                return r;
  59        }
  60        return -1;
  61}
  62
  63static unsigned long basic_get(struct tcf_proto *tp, u32 handle)
  64{
  65        unsigned long l = 0UL;
  66        struct basic_head *head = (struct basic_head *) tp->root;
  67        struct basic_filter *f;
  68
  69        if (head == NULL)
  70                return 0UL;
  71
  72        list_for_each_entry(f, &head->flist, link)
  73                if (f->handle == handle)
  74                        l = (unsigned long) f;
  75
  76        return l;
  77}
  78
  79static void basic_put(struct tcf_proto *tp, unsigned long f)
  80{
  81}
  82
  83static int basic_init(struct tcf_proto *tp)
  84{
  85        struct basic_head *head;
  86
  87        head = kzalloc(sizeof(*head), GFP_KERNEL);
  88        if (head == NULL)
  89                return -ENOBUFS;
  90        INIT_LIST_HEAD(&head->flist);
  91        tp->root = head;
  92        return 0;
  93}
  94
  95static inline void basic_delete_filter(struct tcf_proto *tp,
  96                                       struct basic_filter *f)
  97{
  98        tcf_unbind_filter(tp, &f->res);
  99        tcf_exts_destroy(tp, &f->exts);
 100        tcf_em_tree_destroy(tp, &f->ematches);
 101        kfree(f);
 102}
 103
 104static void basic_destroy(struct tcf_proto *tp)
 105{
 106        struct basic_head *head = tp->root;
 107        struct basic_filter *f, *n;
 108
 109        list_for_each_entry_safe(f, n, &head->flist, link) {
 110                list_del(&f->link);
 111                basic_delete_filter(tp, f);
 112        }
 113        kfree(head);
 114}
 115
 116static int basic_delete(struct tcf_proto *tp, unsigned long arg)
 117{
 118        struct basic_head *head = (struct basic_head *) tp->root;
 119        struct basic_filter *t, *f = (struct basic_filter *) arg;
 120
 121        list_for_each_entry(t, &head->flist, link)
 122                if (t == f) {
 123                        tcf_tree_lock(tp);
 124                        list_del(&t->link);
 125                        tcf_tree_unlock(tp);
 126                        basic_delete_filter(tp, t);
 127                        return 0;
 128                }
 129
 130        return -ENOENT;
 131}
 132
 133static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = {
 134        [TCA_BASIC_CLASSID]     = { .type = NLA_U32 },
 135        [TCA_BASIC_EMATCHES]    = { .type = NLA_NESTED },
 136};
 137
 138static inline int basic_set_parms(struct tcf_proto *tp, struct basic_filter *f,
 139                                  unsigned long base, struct nlattr **tb,
 140                                  struct nlattr *est)
 141{
 142        int err = -EINVAL;
 143        struct tcf_exts e;
 144        struct tcf_ematch_tree t;
 145
 146        err = tcf_exts_validate(tp, tb, est, &e, &basic_ext_map);
 147        if (err < 0)
 148                return err;
 149
 150        err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &t);
 151        if (err < 0)
 152                goto errout;
 153
 154        if (tb[TCA_BASIC_CLASSID]) {
 155                f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]);
 156                tcf_bind_filter(tp, &f->res, base);
 157        }
 158
 159        tcf_exts_change(tp, &f->exts, &e);
 160        tcf_em_tree_change(tp, &f->ematches, &t);
 161
 162        return 0;
 163errout:
 164        tcf_exts_destroy(tp, &e);
 165        return err;
 166}
 167
 168static int basic_change(struct tcf_proto *tp, unsigned long base, u32 handle,
 169                        struct nlattr **tca, unsigned long *arg)
 170{
 171        int err;
 172        struct basic_head *head = (struct basic_head *) tp->root;
 173        struct nlattr *tb[TCA_BASIC_MAX + 1];
 174        struct basic_filter *f = (struct basic_filter *) *arg;
 175
 176        if (tca[TCA_OPTIONS] == NULL)
 177                return -EINVAL;
 178
 179        err = nla_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS],
 180                               basic_policy);
 181        if (err < 0)
 182                return err;
 183
 184        if (f != NULL) {
 185                if (handle && f->handle != handle)
 186                        return -EINVAL;
 187                return basic_set_parms(tp, f, base, tb, tca[TCA_RATE]);
 188        }
 189
 190        err = -ENOBUFS;
 191        f = kzalloc(sizeof(*f), GFP_KERNEL);
 192        if (f == NULL)
 193                goto errout;
 194
 195        err = -EINVAL;
 196        if (handle)
 197                f->handle = handle;
 198        else {
 199                unsigned int i = 0x80000000;
 200                do {
 201                        if (++head->hgenerator == 0x7FFFFFFF)
 202                                head->hgenerator = 1;
 203                } while (--i > 0 && basic_get(tp, head->hgenerator));
 204
 205                if (i <= 0) {
 206                        printk(KERN_ERR "Insufficient number of handles\n");
 207                        goto errout;
 208                }
 209
 210                f->handle = head->hgenerator;
 211        }
 212
 213        err = basic_set_parms(tp, f, base, tb, tca[TCA_RATE]);
 214        if (err < 0)
 215                goto errout;
 216
 217        tcf_tree_lock(tp);
 218        list_add(&f->link, &head->flist);
 219        tcf_tree_unlock(tp);
 220        *arg = (unsigned long) f;
 221
 222        return 0;
 223errout:
 224        if (*arg == 0UL && f)
 225                kfree(f);
 226
 227        return err;
 228}
 229
 230static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 231{
 232        struct basic_head *head = (struct basic_head *) tp->root;
 233        struct basic_filter *f;
 234
 235        list_for_each_entry(f, &head->flist, link) {
 236                if (arg->count < arg->skip)
 237                        goto skip;
 238
 239                if (arg->fn(tp, (unsigned long) f, arg) < 0) {
 240                        arg->stop = 1;
 241                        break;
 242                }
 243skip:
 244                arg->count++;
 245        }
 246}
 247
 248static int basic_dump(struct tcf_proto *tp, unsigned long fh,
 249                      struct sk_buff *skb, struct tcmsg *t)
 250{
 251        struct basic_filter *f = (struct basic_filter *) fh;
 252        struct nlattr *nest;
 253
 254        if (f == NULL)
 255                return skb->len;
 256
 257        t->tcm_handle = f->handle;
 258
 259        nest = nla_nest_start(skb, TCA_OPTIONS);
 260        if (nest == NULL)
 261                goto nla_put_failure;
 262
 263        if (f->res.classid)
 264                NLA_PUT_U32(skb, TCA_BASIC_CLASSID, f->res.classid);
 265
 266        if (tcf_exts_dump(skb, &f->exts, &basic_ext_map) < 0 ||
 267            tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0)
 268                goto nla_put_failure;
 269
 270        nla_nest_end(skb, nest);
 271
 272        if (tcf_exts_dump_stats(skb, &f->exts, &basic_ext_map) < 0)
 273                goto nla_put_failure;
 274
 275        return skb->len;
 276
 277nla_put_failure:
 278        nla_nest_cancel(skb, nest);
 279        return -1;
 280}
 281
 282static struct tcf_proto_ops cls_basic_ops __read_mostly = {
 283        .kind           =       "basic",
 284        .classify       =       basic_classify,
 285        .init           =       basic_init,
 286        .destroy        =       basic_destroy,
 287        .get            =       basic_get,
 288        .put            =       basic_put,
 289        .change         =       basic_change,
 290        .delete         =       basic_delete,
 291        .walk           =       basic_walk,
 292        .dump           =       basic_dump,
 293        .owner          =       THIS_MODULE,
 294};
 295
 296static int __init init_basic(void)
 297{
 298        return register_tcf_proto_ops(&cls_basic_ops);
 299}
 300
 301static void __exit exit_basic(void)
 302{
 303        unregister_tcf_proto_ops(&cls_basic_ops);
 304}
 305
 306module_init(init_basic)
 307module_exit(exit_basic)
 308MODULE_LICENSE("GPL");
 309
 310