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/sched.h>
  16 #include <linux/string.h>
  17 #include <linux/mm.h>
  18 #include <linux/errno.h>
  19 #include <linux/rtnetlink.h>
  20 #include <linux/skbuff.h>
  21 #include <net/act_api.h>
  22 #include <net/pkt_cls.h>
  23
  24 struct basic_head
  25 {
  26         u32                     hgenerator;
  27         struct list_head        flist;
  28 };
  29
  30 struct 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
  39 static struct tcf_ext_map basic_ext_map = {
  40         .action = TCA_BASIC_ACT,
  41         .police = TCA_BASIC_POLICE
  42 };
  43
  44 static 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
  63 static 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
  79 static void basic_put(struct tcf_proto *tp, unsigned long f)
  80 {
  81 }
  82
  83 static int basic_init(struct tcf_proto *tp)
  84 {
  85         return 0;
  86 }
  87
  88 static inline void basic_delete_filter(struct tcf_proto *tp,
  89                                        struct basic_filter *f)
  90 {
  91         tcf_unbind_filter(tp, &f->res);
  92         tcf_exts_destroy(tp, &f->exts);
  93         tcf_em_tree_destroy(tp, &f->ematches);
  94         kfree(f);
  95 }
  96
  97 static void basic_destroy(struct tcf_proto *tp)
  98 {
  99         struct basic_head *head = (struct basic_head *) xchg(&tp->root, NULL);
 100         struct basic_filter *f, *n;
 101
 102         list_for_each_entry_safe(f, n, &head->flist, link) {
 103                 list_del(&f->link);
 104                 basic_delete_filter(tp, f);
 105         }
 106 }
 107
 108 static int basic_delete(struct tcf_proto *tp, unsigned long arg)
 109 {
 110         struct basic_head *head = (struct basic_head *) tp->root;
 111         struct basic_filter *t, *f = (struct basic_filter *) arg;
 112
 113         list_for_each_entry(t, &head->flist, link)
 114                 if (t == f) {
 115                         tcf_tree_lock(tp);
 116                         list_del(&t->link);
 117                         tcf_tree_unlock(tp);
 118                         basic_delete_filter(tp, t);
 119                         return 0;
 120                 }
 121
 122         return -ENOENT;
 123 }
 124
 125 static inline int basic_set_parms(struct tcf_proto *tp, struct basic_filter *f,
 126                                   unsigned long base, struct rtattr **tb,
 127                                   struct rtattr *est)
 128 {
 129         int err = -EINVAL;
 130         struct tcf_exts e;
 131         struct tcf_ematch_tree t;
 132
 133         if (tb[TCA_BASIC_CLASSID-1])
 134                 if (RTA_PAYLOAD(tb[TCA_BASIC_CLASSID-1]) < sizeof(u32))
 135                         return err;
 136
 137         err = tcf_exts_validate(tp, tb, est, &e, &basic_ext_map);
 138         if (err < 0)
 139                 return err;
 140
 141         err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES-1], &t);
 142         if (err < 0)
 143                 goto errout;
 144
 145         if (tb[TCA_BASIC_CLASSID-1]) {
 146                 f->res.classid = *(u32*)RTA_DATA(tb[TCA_BASIC_CLASSID-1]);
 147                 tcf_bind_filter(tp, &f->res, base);
 148         }
 149
 150         tcf_exts_change(tp, &f->exts, &e);
 151         tcf_em_tree_change(tp, &f->ematches, &t);
 152
 153         return 0;
 154 errout:
 155         tcf_exts_destroy(tp, &e);
 156         return err;
 157 }
 158
 159 static int basic_change(struct tcf_proto *tp, unsigned long base, u32 handle,
 160                         struct rtattr **tca, unsigned long *arg)
 161 {
 162         int err = -EINVAL;
 163         struct basic_head *head = (struct basic_head *) tp->root;
 164         struct rtattr *tb[TCA_BASIC_MAX];
 165         struct basic_filter *f = (struct basic_filter *) *arg;
 166
 167         if (tca[TCA_OPTIONS-1] == NULL)
 168                 return -EINVAL;
 169
 170         if (rtattr_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS-1]) < 0)
 171                 return -EINVAL;
 172
 173         if (f != NULL) {
 174                 if (handle && f->handle != handle)
 175                         return -EINVAL;
 176                 return basic_set_parms(tp, f, base, tb, tca[TCA_RATE-1]);
 177         }
 178
 179         err = -ENOBUFS;
 180         if (head == NULL) {
 181                 head = kzalloc(sizeof(*head), GFP_KERNEL);
 182                 if (head == NULL)
 183                         goto errout;
 184
 185                 INIT_LIST_HEAD(&head->flist);
 186                 tp->root = head;
 187         }
 188
 189         f = kzalloc(sizeof(*f), GFP_KERNEL);
 190         if (f == NULL)
 191                 goto errout;
 192
 193         err = -EINVAL;
 194         if (handle)
 195                 f->handle = handle;
 196         else {
 197                 unsigned int i = 0x80000000;
 198                 do {
 199                         if (++head->hgenerator == 0x7FFFFFFF)
 200                                 head->hgenerator = 1;
 201                 } while (--i > 0 && basic_get(tp, head->hgenerator));
 202
 203                 if (i <= 0) {
 204                         printk(KERN_ERR "Insufficient number of handles\n");
 205                         goto errout;
 206                 }
 207
 208                 f->handle = head->hgenerator;
 209         }
 210
 211         err = basic_set_parms(tp, f, base, tb, tca[TCA_RATE-1]);
 212         if (err < 0)
 213                 goto errout;
 214
 215         tcf_tree_lock(tp);
 216         list_add(&f->link, &head->flist);
 217         tcf_tree_unlock(tp);
 218         *arg = (unsigned long) f;
 219
 220         return 0;
 221 errout:
 222         if (*arg == 0UL && f)
 223                 kfree(f);
 224
 225         return err;
 226 }
 227
 228 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 229 {
 230         struct basic_head *head = (struct basic_head *) tp->root;
 231         struct basic_filter *f;
 232
 233         list_for_each_entry(f, &head->flist, link) {
 234                 if (arg->count < arg->skip)
 235                         goto skip;
 236
 237                 if (arg->fn(tp, (unsigned long) f, arg) < 0) {
 238                         arg->stop = 1;
 239                         break;
 240                 }
 241 skip:
 242                 arg->count++;
 243         }
 244 }
 245
 246 static int basic_dump(struct tcf_proto *tp, unsigned long fh,
 247                       struct sk_buff *skb, struct tcmsg *t)
 248 {
 249         struct basic_filter *f = (struct basic_filter *) fh;
 250         unsigned char *b = skb->tail;
 251         struct rtattr *rta;
 252
 253         if (f == NULL)
 254                 return skb->len;
 255
 256         t->tcm_handle = f->handle;
 257
 258         rta = (struct rtattr *) b;
 259         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 260
 261         if (f->res.classid)
 262                 RTA_PUT(skb, TCA_BASIC_CLASSID, sizeof(u32), &f->res.classid);
 263
 264         if (tcf_exts_dump(skb, &f->exts, &basic_ext_map) < 0 ||
 265             tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0)
 266                 goto rtattr_failure;
 267
 268         rta->rta_len = (skb->tail - b);
 269         return skb->len;
 270
 271 rtattr_failure:
 272         skb_trim(skb, b - skb->data);
 273         return -1;
 274 }
 275
 276 static struct tcf_proto_ops cls_basic_ops = {
 277         .kind           =       "basic",
 278         .classify       =       basic_classify,
 279         .init           =       basic_init,
 280         .destroy        =       basic_destroy,
 281         .get            =       basic_get,
 282         .put            =       basic_put,
 283         .change         =       basic_change,
 284         .delete         =       basic_delete,
 285         .walk           =       basic_walk,
 286         .dump           =       basic_dump,
 287         .owner          =       THIS_MODULE,
 288 };
 289
 290 static int __init init_basic(void)
 291 {
 292         return register_tcf_proto_ops(&cls_basic_ops);
 293 }
 294
 295 static void __exit exit_basic(void)
 296 {
 297         unregister_tcf_proto_ops(&cls_basic_ops);
 298 }
 299
 300 module_init(init_basic)
 301 module_exit(exit_basic)
 302 MODULE_LICENSE("GPL");
 303