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         if (tc_should_offload(dev, head->flags))
 116                 mall_destroy_hw_filter(tp, head, (unsigned long) head);
 117
 118         if (tcf_exts_get_net(&head->exts))
 119                 call_rcu(&head->rcu, mall_destroy_rcu);
 120         else
 121                 __mall_destroy(head);
 122 }
 123
 124 static void *mall_get(struct tcf_proto *tp, u32 handle)
 125 {
 126         return NULL;
 127 }
 128
 129 static const struct nla_policy mall_policy[TCA_MATCHALL_MAX + 1] = {
 130         [TCA_MATCHALL_UNSPEC]           = { .type = NLA_UNSPEC },
 131         [TCA_MATCHALL_CLASSID]          = { .type = NLA_U32 },
 132 };
 133
 134 static int mall_set_parms(struct net *net, struct tcf_proto *tp,
 135                           struct cls_mall_head *head,
 136                           unsigned long base, struct nlattr **tb,
 137                           struct nlattr *est, bool ovr)
 138 {
 139         int err;
 140
 141         err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr);
 142         if (err < 0)
 143                 return err;
 144
 145         if (tb[TCA_MATCHALL_CLASSID]) {
 146                 head->res.classid = nla_get_u32(tb[TCA_MATCHALL_CLASSID]);
 147                 tcf_bind_filter(tp, &head->res, base);
 148         }
 149         return 0;
 150 }
 151
 152 static int mall_change(struct net *net, struct sk_buff *in_skb,
 153                        struct tcf_proto *tp, unsigned long base,
 154                        u32 handle, struct nlattr **tca,
 155                        void **arg, bool ovr)
 156 {
 157         struct cls_mall_head *head = rtnl_dereference(tp->root);
 158         struct net_device *dev = tp->q->dev_queue->dev;
 159         struct nlattr *tb[TCA_MATCHALL_MAX + 1];
 160         struct cls_mall_head *new;
 161         u32 flags = 0;
 162         int err;
 163
 164         if (!tca[TCA_OPTIONS])
 165                 return -EINVAL;
 166
 167         if (head)
 168                 return -EEXIST;
 169
 170         err = nla_parse_nested(tb, TCA_MATCHALL_MAX, tca[TCA_OPTIONS],
 171                                mall_policy, NULL);
 172         if (err < 0)
 173                 return err;
 174
 175         if (tb[TCA_MATCHALL_FLAGS]) {
 176                 flags = nla_get_u32(tb[TCA_MATCHALL_FLAGS]);
 177                 if (!tc_flags_valid(flags))
 178                         return -EINVAL;
 179         }
 180
 181         new = kzalloc(sizeof(*new), GFP_KERNEL);
 182         if (!new)
 183                 return -ENOBUFS;
 184
 185         err = tcf_exts_init(&new->exts, TCA_MATCHALL_ACT, 0);
 186         if (err)
 187                 goto err_exts_init;
 188
 189         if (!handle)
 190                 handle = 1;
 191         new->handle = handle;
 192         new->flags = flags;
 193
 194         err = mall_set_parms(net, tp, new, base, tb, tca[TCA_RATE], ovr);
 195         if (err)
 196                 goto err_set_parms;
 197
 198         if (tc_should_offload(dev, flags)) {
 199                 err = mall_replace_hw_filter(tp, new, (unsigned long) new);
 200                 if (err) {
 201                         if (tc_skip_sw(flags))
 202                                 goto err_replace_hw_filter;
 203                         else
 204                                 err = 0;
 205                 }
 206         }
 207
 208         if (!tc_in_hw(new->flags))
 209                 new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
 210
 211         *arg = head;
 212         rcu_assign_pointer(tp->root, new);
 213         return 0;
 214
 215 err_replace_hw_filter:
 216 err_set_parms:
 217         tcf_exts_destroy(&new->exts);
 218 err_exts_init:
 219         kfree(new);
 220         return err;
 221 }
 222
 223 static int mall_delete(struct tcf_proto *tp, void *arg, bool *last)
 224 {
 225         return -EOPNOTSUPP;
 226 }
 227
 228 static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 229 {
 230         struct cls_mall_head *head = rtnl_dereference(tp->root);
 231
 232         if (arg->count < arg->skip)
 233                 goto skip;
 234         if (arg->fn(tp, head, arg) < 0)
 235                 arg->stop = 1;
 236 skip:
 237         arg->count++;
 238 }
 239
 240 static int mall_dump(struct net *net, struct tcf_proto *tp, void *fh,
 241                      struct sk_buff *skb, struct tcmsg *t)
 242 {
 243         struct cls_mall_head *head = fh;
 244         struct nlattr *nest;
 245
 246         if (!head)
 247                 return skb->len;
 248
 249         t->tcm_handle = head->handle;
 250
 251         nest = nla_nest_start(skb, TCA_OPTIONS);
 252         if (!nest)
 253                 goto nla_put_failure;
 254
 255         if (head->res.classid &&
 256             nla_put_u32(skb, TCA_MATCHALL_CLASSID, head->res.classid))
 257                 goto nla_put_failure;
 258
 259         if (head->flags && nla_put_u32(skb, TCA_MATCHALL_FLAGS, head->flags))
 260                 goto nla_put_failure;
 261
 262         if (tcf_exts_dump(skb, &head->exts))
 263                 goto nla_put_failure;
 264
 265         nla_nest_end(skb, nest);
 266
 267         if (tcf_exts_dump_stats(skb, &head->exts) < 0)
 268                 goto nla_put_failure;
 269
 270         return skb->len;
 271
 272 nla_put_failure:
 273         nla_nest_cancel(skb, nest);
 274         return -1;
 275 }
 276
 277 static void mall_bind_class(void *fh, u32 classid, unsigned long cl)
 278 {
 279         struct cls_mall_head *head = fh;
 280
 281         if (head && head->res.classid == classid)
 282                 head->res.class = cl;
 283 }
 284
 285 static struct tcf_proto_ops cls_mall_ops __read_mostly = {
 286         .kind           = "matchall",
 287         .classify       = mall_classify,
 288         .init           = mall_init,
 289         .destroy        = mall_destroy,
 290         .get            = mall_get,
 291         .change         = mall_change,
 292         .delete         = mall_delete,
 293         .walk           = mall_walk,
 294         .dump           = mall_dump,
 295         .bind_class     = mall_bind_class,
 296         .owner          = THIS_MODULE,
 297 };
 298
 299 static int __init cls_mall_init(void)
 300 {
 301         return register_tcf_proto_ops(&cls_mall_ops);
 302 }
 303
 304 static void __exit cls_mall_exit(void)
 305 {
 306         unregister_tcf_proto_ops(&cls_mall_ops);
 307 }
 308
 309 module_init(cls_mall_init);
 310 module_exit(cls_mall_exit);
 311
 312 MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
 313 MODULE_DESCRIPTION("Match-all classifier");
 314 MODULE_LICENSE("GPL v2");