net/sched/cls_basic.c

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