net/sched/cls_matchall.c

   1 /*
   2  * net/sched/cls_matchll.c              Match-all classifier
   3  *
   4  * Copyright (c) 2016 Jiri Pirko <jiri@mellanox.com>
   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 int mall_replace_hw_filter(struct tcf_proto *tp,
  73                                   struct cls_mall_head *head,
  74                                   unsigned long cookie)
  75 {
  76         struct net_device *dev = tp->q->dev_queue->dev;
  77         struct tc_cls_matchall_offload cls_mall = {};
  78         int err;
  79
  80         tc_cls_common_offload_init(&cls_mall.common, tp);
  81         cls_mall.command = TC_CLSMATCHALL_REPLACE;
  82         cls_mall.exts = &head->exts;
  83         cls_mall.cookie = cookie;
  84
  85         err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_CLSMATCHALL,
  86                                             &cls_mall);
  87         if (!err)
  88                 head->flags |= TCA_CLS_FLAGS_IN_HW;
  89
  90         return err;
  91 }
  92
  93 static void mall_destroy_hw_filter(struct tcf_proto *tp,
  94                                    struct cls_mall_head *head,
  95                                    unsigned long cookie)
  96 {
  97         struct net_device *dev = tp->q->dev_queue->dev;
  98         struct tc_cls_matchall_offload cls_mall = {};
  99
 100         tc_cls_common_offload_init(&cls_mall.common, tp);
 101         cls_mall.command = TC_CLSMATCHALL_DESTROY;
 102         cls_mall.cookie = cookie;
 103
 104         dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_CLSMATCHALL, &cls_mall);
 105 }
 106
 107 static void mall_destroy(struct tcf_proto *tp)
 108 {
 109         struct cls_mall_head *head = rtnl_dereference(tp->root);
 110         struct net_device *dev = tp->q->dev_queue->dev;
 111
 112         if (!head)
 113                 return;
 114
 115         tcf_unbind_filter(tp, &head->res);
 116
 117         if (tc_should_offload(dev, head->flags))
 118                 mall_destroy_hw_filter(tp, head, (unsigned long) head);
 119
 120         if (tcf_exts_get_net(&head->exts))
 121                 call_rcu(&head->rcu, mall_destroy_rcu);
 122         else
 123                 __mall_destroy(head);
 124 }
 125
 126 static void *mall_get(struct tcf_proto *tp, u32 handle)
 127 {
 128         struct cls_mall_head *head = rtnl_dereference(tp->root);
 129
 130         if (head && head->handle == handle)
 131                 return head;
 132
 133         return NULL;
 134 }
 135
 136 static const struct nla_policy mall_policy[TCA_MATCHALL_MAX + 1] = {
 137         [TCA_MATCHALL_UNSPEC]           = { .type = NLA_UNSPEC },
 138         [TCA_MATCHALL_CLASSID]          = { .type = NLA_U32 },
 139         [TCA_MATCHALL_FLAGS]            = { .type = NLA_U32 },
 140 };
 141
 142 static int mall_set_parms(struct net *net, struct tcf_proto *tp,
 143                           struct cls_mall_head *head,
 144                           unsigned long base, struct nlattr **tb,
 145                           struct nlattr *est, bool ovr)
 146 {
 147         int err;
 148
 149         err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr);
 150         if (err < 0)
 151                 return err;
 152
 153         if (tb[TCA_MATCHALL_CLASSID]) {
 154                 head->res.classid = nla_get_u32(tb[TCA_MATCHALL_CLASSID]);
 155                 tcf_bind_filter(tp, &head->res, base);
 156         }
 157         return 0;
 158 }
 159
 160 static int mall_change(struct net *net, struct sk_buff *in_skb,
 161                        struct tcf_proto *tp, unsigned long base,
 162                        u32 handle, struct nlattr **tca,
 163                        void **arg, bool ovr)
 164 {
 165         struct cls_mall_head *head = rtnl_dereference(tp->root);
 166         struct net_device *dev = tp->q->dev_queue->dev;
 167         struct nlattr *tb[TCA_MATCHALL_MAX + 1];
 168         struct cls_mall_head *new;
 169         u32 flags = 0;
 170         int err;
 171
 172         if (!tca[TCA_OPTIONS])
 173                 return -EINVAL;
 174
 175         if (head)
 176                 return -EEXIST;
 177
 178         err = nla_parse_nested(tb, TCA_MATCHALL_MAX, tca[TCA_OPTIONS],
 179                                mall_policy, NULL);
 180         if (err < 0)
 181                 return err;
 182
 183         if (tb[TCA_MATCHALL_FLAGS]) {
 184                 flags = nla_get_u32(tb[TCA_MATCHALL_FLAGS]);
 185                 if (!tc_flags_valid(flags))
 186                         return -EINVAL;
 187         }
 188
 189         new = kzalloc(sizeof(*new), GFP_KERNEL);
 190         if (!new)
 191                 return -ENOBUFS;
 192
 193         err = tcf_exts_init(&new->exts, TCA_MATCHALL_ACT, 0);
 194         if (err)
 195                 goto err_exts_init;
 196
 197         if (!handle)
 198                 handle = 1;
 199         new->handle = handle;
 200         new->flags = flags;
 201
 202         err = mall_set_parms(net, tp, new, base, tb, tca[TCA_RATE], ovr);
 203         if (err)
 204                 goto err_set_parms;
 205
 206         if (tc_should_offload(dev, flags)) {
 207                 err = mall_replace_hw_filter(tp, new, (unsigned long) new);
 208                 if (err) {
 209                         if (tc_skip_sw(flags))
 210                                 goto err_replace_hw_filter;
 211                         else
 212                                 err = 0;
 213                 }
 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 {
 233         return -EOPNOTSUPP;
 234 }
 235
 236 static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 237 {
 238         struct cls_mall_head *head = rtnl_dereference(tp->root);
 239
 240         if (arg->count < arg->skip)
 241                 goto skip;
 242         if (arg->fn(tp, head, arg) < 0)
 243                 arg->stop = 1;
 244 skip:
 245         arg->count++;
 246 }
 247
 248 static int mall_dump(struct net *net, struct tcf_proto *tp, void *fh,
 249                      struct sk_buff *skb, struct tcmsg *t)
 250 {
 251         struct cls_mall_head *head = fh;
 252         struct nlattr *nest;
 253
 254         if (!head)
 255                 return skb->len;
 256
 257         t->tcm_handle = head->handle;
 258
 259         nest = nla_nest_start(skb, TCA_OPTIONS);
 260         if (!nest)
 261                 goto nla_put_failure;
 262
 263         if (head->res.classid &&
 264             nla_put_u32(skb, TCA_MATCHALL_CLASSID, head->res.classid))
 265                 goto nla_put_failure;
 266
 267         if (head->flags && nla_put_u32(skb, TCA_MATCHALL_FLAGS, head->flags))
 268                 goto nla_put_failure;
 269
 270         if (tcf_exts_dump(skb, &head->exts))
 271                 goto nla_put_failure;
 272
 273         nla_nest_end(skb, nest);
 274
 275         if (tcf_exts_dump_stats(skb, &head->exts) < 0)
 276                 goto nla_put_failure;
 277
 278         return skb->len;
 279
 280 nla_put_failure:
 281         nla_nest_cancel(skb, nest);
 282         return -1;
 283 }
 284
 285 static void mall_bind_class(void *fh, u32 classid, unsigned long cl)
 286 {
 287         struct cls_mall_head *head = fh;
 288
 289         if (head && head->res.classid == classid)
 290                 head->res.class = cl;
 291 }
 292
 293 static struct tcf_proto_ops cls_mall_ops __read_mostly = {
 294         .kind           = "matchall",
 295         .classify       = mall_classify,
 296         .init           = mall_init,
 297         .destroy        = mall_destroy,
 298         .get            = mall_get,
 299         .change         = mall_change,
 300         .delete         = mall_delete,
 301         .walk           = mall_walk,
 302         .dump           = mall_dump,
 303         .bind_class     = mall_bind_class,
 304         .owner          = THIS_MODULE,
 305 };
 306
 307 static int __init cls_mall_init(void)
 308 {
 309         return register_tcf_proto_ops(&cls_mall_ops);
 310 }
 311
 312 static void __exit cls_mall_exit(void)
 313 {
 314         unregister_tcf_proto_ops(&cls_mall_ops);
 315 }
 316
 317 module_init(cls_mall_init);
 318 module_exit(cls_mall_exit);
 319
 320 MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
 321 MODULE_DESCRIPTION("Match-all classifier");
 322 MODULE_LICENSE("GPL v2");