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