net/sched/cls_matchall.c

   1 /*
   2  * net/sched/cls_matchll.c              Match-all classifier
   3  *
   4  * Copyright (c) 2016 Jiri Pirko <[email protected]>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/module.h>
  15
  16 #include <net/sch_generic.h>
  17 #include <net/pkt_cls.h>
  18
  19 struct cls_mall_head {
  20         struct tcf_exts exts;
  21         struct tcf_result res;
  22         u32 handle;
  23         u32 flags;
  24         union {
  25                 struct work_struct work;
  26                 struct rcu_head rcu;
  27         };
  28 };
  29
  30 static int mall_classify(struct sk_buff *skb, const struct tcf_proto *tp,
  31                          struct tcf_result *res)
  32 {
  33         struct cls_mall_head *head = rcu_dereference_bh(tp->root);
  34
  35         if (tc_skip_sw(head->flags))
  36                 return -1;
  37
  38         *res = head->res;
  39         return tcf_exts_exec(skb, &head->exts, res);
  40 }
  41
  42 static int mall_init(struct tcf_proto *tp)
  43 {
  44         return 0;
  45 }
  46
  47 static void __mall_destroy(struct cls_mall_head *head)
  48 {
  49         tcf_exts_destroy(&head->exts);
  50         tcf_exts_put_net(&head->exts);
  51         kfree(head);
  52 }
  53
  54 static void mall_destroy_work(struct work_struct *work)
  55 {
  56         struct cls_mall_head *head = container_of(work, struct cls_mall_head,
  57                                                   work);
  58         rtnl_lock();
  59         __mall_destroy(head);
  60         rtnl_unlock();
  61 }
  62
  63 static void mall_destroy_rcu(struct rcu_head *rcu)
  64 {
  65         struct cls_mall_head *head = container_of(rcu, struct cls_mall_head,
  66                                                   rcu);
  67
  68         INIT_WORK(&head->work, mall_destroy_work);
  69         tcf_queue_work(&head->work);
  70 }
  71
  72 static void mall_destroy_hw_filter(struct tcf_proto *tp,
  73                                    struct cls_mall_head *head,
  74                                    unsigned long cookie,
  75                                    struct netlink_ext_ack *extack)
  76 {
  77         struct tc_cls_matchall_offload cls_mall = {};
  78         struct tcf_block *block = tp->chain->block;
  79
  80         tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, extack);
  81         cls_mall.command = TC_CLSMATCHALL_DESTROY;
  82         cls_mall.cookie = cookie;
  83
  84         tc_setup_cb_call(block, NULL, TC_SETUP_CLSMATCHALL, &cls_mall, false);
  85         tcf_block_offload_dec(block, &head->flags);
  86 }
  87
  88 static int mall_replace_hw_filter(struct tcf_proto *tp,
  89                                   struct cls_mall_head *head,
  90                                   unsigned long cookie,
  91                                   struct netlink_ext_ack *extack)
  92 {
  93         struct tc_cls_matchall_offload cls_mall = {};
  94         struct tcf_block *block = tp->chain->block;
  95         bool skip_sw = tc_skip_sw(head->flags);
  96         int err;
  97
  98         tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, extack);
  99         cls_mall.command = TC_CLSMATCHALL_REPLACE;
 100         cls_mall.exts = &head->exts;
 101         cls_mall.cookie = cookie;
 102
 103         err = tc_setup_cb_call(block, NULL, TC_SETUP_CLSMATCHALL,
 104                                &cls_mall, skip_sw);
 105         if (err < 0) {
 106                 mall_destroy_hw_filter(tp, head, cookie, NULL);
 107                 return err;
 108         } else if (err > 0) {
 109                 tcf_block_offload_inc(block, &head->flags);
 110         }
 111
 112         if (skip_sw && !(head->flags & TCA_CLS_FLAGS_IN_HW))
 113                 return -EINVAL;
 114
 115         return 0;
 116 }
 117
 118 static void mall_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
 119 {
 120         struct cls_mall_head *head = rtnl_dereference(tp->root);
 121
 122         if (!head)
 123                 return;
 124
 125         if (!tc_skip_hw(head->flags))
 126                 mall_destroy_hw_filter(tp, head, (unsigned long) head, extack);
 127
 128         if (tcf_exts_get_net(&head->exts))
 129                 call_rcu(&head->rcu, mall_destroy_rcu);
 130         else
 131                 __mall_destroy(head);
 132 }
 133
 134 static void *mall_get(struct tcf_proto *tp, u32 handle)
 135 {
 136         return NULL;
 137 }
 138
 139 static const struct nla_policy mall_policy[TCA_MATCHALL_MAX + 1] = {
 140         [TCA_MATCHALL_UNSPEC]           = { .type = NLA_UNSPEC },
 141         [TCA_MATCHALL_CLASSID]          = { .type = NLA_U32 },
 142 };
 143
 144 static int mall_set_parms(struct net *net, struct tcf_proto *tp,
 145                           struct cls_mall_head *head,
 146                           unsigned long base, struct nlattr **tb,
 147                           struct nlattr *est, bool ovr,
 148                           struct netlink_ext_ack *extack)
 149 {
 150         int err;
 151
 152         err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr, extack);
 153         if (err < 0)
 154                 return err;
 155
 156         if (tb[TCA_MATCHALL_CLASSID]) {
 157                 head->res.classid = nla_get_u32(tb[TCA_MATCHALL_CLASSID]);
 158                 tcf_bind_filter(tp, &head->res, base);
 159         }
 160         return 0;
 161 }
 162
 163 static int mall_change(struct net *net, struct sk_buff *in_skb,
 164                        struct tcf_proto *tp, unsigned long base,
 165                        u32 handle, struct nlattr **tca,
 166                        void **arg, bool ovr, struct netlink_ext_ack *extack)
 167 {
 168         struct cls_mall_head *head = rtnl_dereference(tp->root);
 169         struct nlattr *tb[TCA_MATCHALL_MAX + 1];
 170         struct cls_mall_head *new;
 171         u32 flags = 0;
 172         int err;
 173
 174         if (!tca[TCA_OPTIONS])
 175                 return -EINVAL;
 176
 177         if (head)
 178                 return -EEXIST;
 179
 180         err = nla_parse_nested(tb, TCA_MATCHALL_MAX, tca[TCA_OPTIONS],
 181                                mall_policy, NULL);
 182         if (err < 0)
 183                 return err;
 184
 185         if (tb[TCA_MATCHALL_FLAGS]) {
 186                 flags = nla_get_u32(tb[TCA_MATCHALL_FLAGS]);
 187                 if (!tc_flags_valid(flags))
 188                         return -EINVAL;
 189         }
 190
 191         new = kzalloc(sizeof(*new), GFP_KERNEL);
 192         if (!new)
 193                 return -ENOBUFS;
 194
 195         err = tcf_exts_init(&new->exts, TCA_MATCHALL_ACT, 0);
 196         if (err)
 197                 goto err_exts_init;
 198
 199         if (!handle)
 200                 handle = 1;
 201         new->handle = handle;
 202         new->flags = flags;
 203
 204         err = mall_set_parms(net, tp, new, base, tb, tca[TCA_RATE], ovr,
 205                              extack);
 206         if (err)
 207                 goto err_set_parms;
 208
 209         if (!tc_skip_hw(new->flags)) {
 210                 err = mall_replace_hw_filter(tp, new, (unsigned long)new,
 211                                              extack);
 212                 if (err)
 213                         goto err_replace_hw_filter;
 214         }
 215
 216         if (!tc_in_hw(new->flags))
 217                 new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
 218
 219         *arg = head;
 220         rcu_assign_pointer(tp->root, new);
 221         return 0;
 222
 223 err_replace_hw_filter:
 224 err_set_parms:
 225         tcf_exts_destroy(&new->exts);
 226 err_exts_init:
 227         kfree(new);
 228         return err;
 229 }
 230
 231 static int mall_delete(struct tcf_proto *tp, void *arg, bool *last,
 232                        struct netlink_ext_ack *extack)
 233 {
 234         return -EOPNOTSUPP;
 235 }
 236
 237 static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 238 {
 239         struct cls_mall_head *head = rtnl_dereference(tp->root);
 240
 241         if (arg->count < arg->skip)
 242                 goto skip;
 243         if (arg->fn(tp, head, arg) < 0)
 244                 arg->stop = 1;
 245 skip:
 246         arg->count++;
 247 }
 248
 249 static int mall_dump(struct net *net, struct tcf_proto *tp, void *fh,
 250                      struct sk_buff *skb, struct tcmsg *t)
 251 {
 252         struct cls_mall_head *head = fh;
 253         struct nlattr *nest;
 254
 255         if (!head)
 256                 return skb->len;
 257
 258         t->tcm_handle = head->handle;
 259
 260         nest = nla_nest_start(skb, TCA_OPTIONS);
 261         if (!nest)
 262                 goto nla_put_failure;
 263
 264         if (head->res.classid &&
 265             nla_put_u32(skb, TCA_MATCHALL_CLASSID, head->res.classid))
 266                 goto nla_put_failure;
 267
 268         if (head->flags && nla_put_u32(skb, TCA_MATCHALL_FLAGS, head->flags))
 269                 goto nla_put_failure;
 270
 271         if (tcf_exts_dump(skb, &head->exts))
 272                 goto nla_put_failure;
 273
 274         nla_nest_end(skb, nest);
 275
 276         if (tcf_exts_dump_stats(skb, &head->exts) < 0)
 277                 goto nla_put_failure;
 278
 279         return skb->len;
 280
 281 nla_put_failure:
 282         nla_nest_cancel(skb, nest);
 283         return -1;
 284 }
 285
 286 static void mall_bind_class(void *fh, u32 classid, unsigned long cl)
 287 {
 288         struct cls_mall_head *head = fh;
 289
 290         if (head && head->res.classid == classid)
 291                 head->res.class = cl;
 292 }
 293
 294 static struct tcf_proto_ops cls_mall_ops __read_mostly = {
 295         .kind           = "matchall",
 296         .classify       = mall_classify,
 297         .init           = mall_init,
 298         .destroy        = mall_destroy,
 299         .get            = mall_get,
 300         .change         = mall_change,
 301         .delete         = mall_delete,
 302         .walk           = mall_walk,
 303         .dump           = mall_dump,
 304         .bind_class     = mall_bind_class,
 305         .owner          = THIS_MODULE,
 306 };
 307
 308 static int __init cls_mall_init(void)
 309 {
 310         return register_tcf_proto_ops(&cls_mall_ops);
 311 }
 312
 313 static void __exit cls_mall_exit(void)
 314 {
 315         unregister_tcf_proto_ops(&cls_mall_ops);
 316 }
 317
 318 module_init(cls_mall_init);
 319 module_exit(cls_mall_exit);
 320
 321 MODULE_AUTHOR("Jiri Pirko <[email protected]>");
 322 MODULE_DESCRIPTION("Match-all classifier");
 323 MODULE_LICENSE("GPL v2");