net/sched/cls_basic.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/sched/cls_basic.c        Basic Packet Classifier.
   4  *
   5  * Authors:     Thomas Graf <tgraf@suug.ch>
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/slab.h>
  10 #include <linux/types.h>
  11 #include <linux/kernel.h>
  12 #include <linux/string.h>
  13 #include <linux/errno.h>
  14 #include <linux/rtnetlink.h>
  15 #include <linux/skbuff.h>
  16 #include <linux/idr.h>
  17 #include <linux/percpu.h>
  18 #include <net/netlink.h>
  19 #include <net/act_api.h>
  20 #include <net/pkt_cls.h>
  21
  22 struct basic_head {
  23         struct list_head        flist;
  24         struct idr              handle_idr;
  25         struct rcu_head         rcu;
  26 };
  27
  28 struct basic_filter {
  29         u32                     handle;
  30         struct tcf_exts         exts;
  31         struct tcf_ematch_tree  ematches;
  32         struct tcf_result       res;
  33         struct tcf_proto        *tp;
  34         struct list_head        link;
  35         struct tc_basic_pcnt __percpu *pf;
  36         struct rcu_work         rwork;
  37 };
  38
  39 static int basic_classify(struct sk_buff *skb, const struct tcf_proto *tp,
  40                           struct tcf_result *res)
  41 {
  42         int r;
  43         struct basic_head *head = rcu_dereference_bh(tp->root);
  44         struct basic_filter *f;
  45
  46         list_for_each_entry_rcu(f, &head->flist, link) {
  47                 __this_cpu_inc(f->pf->rcnt);
  48                 if (!tcf_em_tree_match(skb, &f->ematches, NULL))
  49                         continue;
  50                 __this_cpu_inc(f->pf->rhit);
  51                 *res = f->res;
  52                 r = tcf_exts_exec(skb, &f->exts, res);
  53                 if (r < 0)
  54                         continue;
  55                 return r;
  56         }
  57         return -1;
  58 }
  59
  60 static void *basic_get(struct tcf_proto *tp, u32 handle)
  61 {
  62         struct basic_head *head = rtnl_dereference(tp->root);
  63         struct basic_filter *f;
  64
  65         list_for_each_entry(f, &head->flist, link) {
  66                 if (f->handle == handle) {
  67                         return f;
  68                 }
  69         }
  70
  71         return NULL;
  72 }
  73
  74 static int basic_init(struct tcf_proto *tp)
  75 {
  76         struct basic_head *head;
  77
  78         head = kzalloc(sizeof(*head), GFP_KERNEL);
  79         if (head == NULL)
  80                 return -ENOBUFS;
  81         INIT_LIST_HEAD(&head->flist);
  82         idr_init(&head->handle_idr);
  83         rcu_assign_pointer(tp->root, head);
  84         return 0;
  85 }
  86
  87 static void __basic_delete_filter(struct basic_filter *f)
  88 {
  89         tcf_exts_destroy(&f->exts);
  90         tcf_em_tree_destroy(&f->ematches);
  91         tcf_exts_put_net(&f->exts);
  92         free_percpu(f->pf);
  93         kfree(f);
  94 }
  95
  96 static void basic_delete_filter_work(struct work_struct *work)
  97 {
  98         struct basic_filter *f = container_of(to_rcu_work(work),
  99                                               struct basic_filter,
 100                                               rwork);
 101         rtnl_lock();
 102         __basic_delete_filter(f);
 103         rtnl_unlock();
 104 }
 105
 106 static void basic_destroy(struct tcf_proto *tp, bool rtnl_held,
 107                           struct netlink_ext_ack *extack)
 108 {
 109         struct basic_head *head = rtnl_dereference(tp->root);
 110         struct basic_filter *f, *n;
 111
 112         list_for_each_entry_safe(f, n, &head->flist, link) {
 113                 list_del_rcu(&f->link);
 114                 tcf_unbind_filter(tp, &f->res);
 115                 idr_remove(&head->handle_idr, f->handle);
 116                 if (tcf_exts_get_net(&f->exts))
 117                         tcf_queue_work(&f->rwork, basic_delete_filter_work);
 118                 else
 119                         __basic_delete_filter(f);
 120         }
 121         idr_destroy(&head->handle_idr);
 122         kfree_rcu(head, rcu);
 123 }
 124
 125 static int basic_delete(struct tcf_proto *tp, void *arg, bool *last,
 126                         bool rtnl_held, struct netlink_ext_ack *extack)
 127 {
 128         struct basic_head *head = rtnl_dereference(tp->root);
 129         struct basic_filter *f = arg;
 130
 131         list_del_rcu(&f->link);
 132         tcf_unbind_filter(tp, &f->res);
 133         idr_remove(&head->handle_idr, f->handle);
 134         tcf_exts_get_net(&f->exts);
 135         tcf_queue_work(&f->rwork, basic_delete_filter_work);
 136         *last = list_empty(&head->flist);
 137         return 0;
 138 }
 139
 140 static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = {
 141         [TCA_BASIC_CLASSID]     = { .type = NLA_U32 },
 142         [TCA_BASIC_EMATCHES]    = { .type = NLA_NESTED },
 143 };
 144
 145 static int basic_set_parms(struct net *net, struct tcf_proto *tp,
 146                            struct basic_filter *f, unsigned long base,
 147                            struct nlattr **tb,
 148                            struct nlattr *est, u32 flags,
 149                            struct netlink_ext_ack *extack)
 150 {
 151         int err;
 152
 153         err = tcf_exts_validate(net, tp, tb, est, &f->exts, flags, extack);
 154         if (err < 0)
 155                 return err;
 156
 157         err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &f->ematches);
 158         if (err < 0)
 159                 return err;
 160
 161         if (tb[TCA_BASIC_CLASSID]) {
 162                 f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]);
 163                 tcf_bind_filter(tp, &f->res, base);
 164         }
 165
 166         f->tp = tp;
 167         return 0;
 168 }
 169
 170 static int basic_change(struct net *net, struct sk_buff *in_skb,
 171                         struct tcf_proto *tp, unsigned long base, u32 handle,
 172                         struct nlattr **tca, void **arg,
 173                         u32 flags, struct netlink_ext_ack *extack)
 174 {
 175         int err;
 176         struct basic_head *head = rtnl_dereference(tp->root);
 177         struct nlattr *tb[TCA_BASIC_MAX + 1];
 178         struct basic_filter *fold = (struct basic_filter *) *arg;
 179         struct basic_filter *fnew;
 180
 181         if (tca[TCA_OPTIONS] == NULL)
 182                 return -EINVAL;
 183
 184         err = nla_parse_nested_deprecated(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS],
 185                                           basic_policy, NULL);
 186         if (err < 0)
 187                 return err;
 188
 189         if (fold != NULL) {
 190                 if (handle && fold->handle != handle)
 191                         return -EINVAL;
 192         }
 193
 194         fnew = kzalloc(sizeof(*fnew), GFP_KERNEL);
 195         if (!fnew)
 196                 return -ENOBUFS;
 197
 198         err = tcf_exts_init(&fnew->exts, net, TCA_BASIC_ACT, TCA_BASIC_POLICE);
 199         if (err < 0)
 200                 goto errout;
 201
 202         if (!handle) {
 203                 handle = 1;
 204                 err = idr_alloc_u32(&head->handle_idr, fnew, &handle,
 205                                     INT_MAX, GFP_KERNEL);
 206         } else if (!fold) {
 207                 err = idr_alloc_u32(&head->handle_idr, fnew, &handle,
 208                                     handle, GFP_KERNEL);
 209         }
 210         if (err)
 211                 goto errout;
 212         fnew->handle = handle;
 213         fnew->pf = alloc_percpu(struct tc_basic_pcnt);
 214         if (!fnew->pf) {
 215                 err = -ENOMEM;
 216                 goto errout;
 217         }
 218
 219         err = basic_set_parms(net, tp, fnew, base, tb, tca[TCA_RATE], flags,
 220                               extack);
 221         if (err < 0) {
 222                 if (!fold)
 223                         idr_remove(&head->handle_idr, fnew->handle);
 224                 goto errout;
 225         }
 226
 227         *arg = fnew;
 228
 229         if (fold) {
 230                 idr_replace(&head->handle_idr, fnew, fnew->handle);
 231                 list_replace_rcu(&fold->link, &fnew->link);
 232                 tcf_unbind_filter(tp, &fold->res);
 233                 tcf_exts_get_net(&fold->exts);
 234                 tcf_queue_work(&fold->rwork, basic_delete_filter_work);
 235         } else {
 236                 list_add_rcu(&fnew->link, &head->flist);
 237         }
 238
 239         return 0;
 240 errout:
 241         free_percpu(fnew->pf);
 242         tcf_exts_destroy(&fnew->exts);
 243         kfree(fnew);
 244         return err;
 245 }
 246
 247 static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg,
 248                        bool rtnl_held)
 249 {
 250         struct basic_head *head = rtnl_dereference(tp->root);
 251         struct basic_filter *f;
 252
 253         list_for_each_entry(f, &head->flist, link) {
 254                 if (arg->count < arg->skip)
 255                         goto skip;
 256
 257                 if (arg->fn(tp, f, arg) < 0) {
 258                         arg->stop = 1;
 259                         break;
 260                 }
 261 skip:
 262                 arg->count++;
 263         }
 264 }
 265
 266 static void basic_bind_class(void *fh, u32 classid, unsigned long cl, void *q,
 267                              unsigned long base)
 268 {
 269         struct basic_filter *f = fh;
 270
 271         if (f && f->res.classid == classid) {
 272                 if (cl)
 273                         __tcf_bind_filter(q, &f->res, base);
 274                 else
 275                         __tcf_unbind_filter(q, &f->res);
 276         }
 277 }
 278
 279 static int basic_dump(struct net *net, struct tcf_proto *tp, void *fh,
 280                       struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 281 {
 282         struct tc_basic_pcnt gpf = {};
 283         struct basic_filter *f = fh;
 284         struct nlattr *nest;
 285         int cpu;
 286
 287         if (f == NULL)
 288                 return skb->len;
 289
 290         t->tcm_handle = f->handle;
 291
 292         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 293         if (nest == NULL)
 294                 goto nla_put_failure;
 295
 296         if (f->res.classid &&
 297             nla_put_u32(skb, TCA_BASIC_CLASSID, f->res.classid))
 298                 goto nla_put_failure;
 299
 300         for_each_possible_cpu(cpu) {
 301                 struct tc_basic_pcnt *pf = per_cpu_ptr(f->pf, cpu);
 302
 303                 gpf.rcnt += pf->rcnt;
 304                 gpf.rhit += pf->rhit;
 305         }
 306
 307         if (nla_put_64bit(skb, TCA_BASIC_PCNT,
 308                           sizeof(struct tc_basic_pcnt),
 309                           &gpf, TCA_BASIC_PAD))
 310                 goto nla_put_failure;
 311
 312         if (tcf_exts_dump(skb, &f->exts) < 0 ||
 313             tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0)
 314                 goto nla_put_failure;
 315
 316         nla_nest_end(skb, nest);
 317
 318         if (tcf_exts_dump_stats(skb, &f->exts) < 0)
 319                 goto nla_put_failure;
 320
 321         return skb->len;
 322
 323 nla_put_failure:
 324         nla_nest_cancel(skb, nest);
 325         return -1;
 326 }
 327
 328 static struct tcf_proto_ops cls_basic_ops __read_mostly = {
 329         .kind           =       "basic",
 330         .classify       =       basic_classify,
 331         .init           =       basic_init,
 332         .destroy        =       basic_destroy,
 333         .get            =       basic_get,
 334         .change         =       basic_change,
 335         .delete         =       basic_delete,
 336         .walk           =       basic_walk,
 337         .dump           =       basic_dump,
 338         .bind_class     =       basic_bind_class,
 339         .owner          =       THIS_MODULE,
 340 };
 341
 342 static int __init init_basic(void)
 343 {
 344         return register_tcf_proto_ops(&cls_basic_ops);
 345 }
 346
 347 static void __exit exit_basic(void)
 348 {
 349         unregister_tcf_proto_ops(&cls_basic_ops);
 350 }
 351
 352 module_init(init_basic)
 353 module_exit(exit_basic)
 354 MODULE_LICENSE("GPL");