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         struct rcu_head rcu;
  25 };
  26
  27 static int mall_classify(struct sk_buff *skb, const struct tcf_proto *tp,
  28                          struct tcf_result *res)
  29 {
  30         struct cls_mall_head *head = rcu_dereference_bh(tp->root);
  31
  32         if (tc_skip_sw(head->flags))
  33                 return -1;
  34
  35         *res = head->res;
  36         return tcf_exts_exec(skb, &head->exts, res);
  37 }
  38
  39 static int mall_init(struct tcf_proto *tp)
  40 {
  41         return 0;
  42 }
  43
  44 static void mall_destroy_rcu(struct rcu_head *rcu)
  45 {
  46         struct cls_mall_head *head = container_of(rcu, struct cls_mall_head,
  47                                                   rcu);
  48
  49         tcf_exts_destroy(&head->exts);
  50         kfree(head);
  51 }
  52
  53 static int mall_replace_hw_filter(struct tcf_proto *tp,
  54                                   struct cls_mall_head *head,
  55                                   unsigned long cookie)
  56 {
  57         struct net_device *dev = tp->q->dev_queue->dev;
  58         struct tc_cls_matchall_offload cls_mall = {};
  59         int err;
  60
  61         tc_cls_common_offload_init(&cls_mall.common, tp);
  62         cls_mall.command = TC_CLSMATCHALL_REPLACE;
  63         cls_mall.exts = &head->exts;
  64         cls_mall.cookie = cookie;
  65
  66         err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_CLSMATCHALL,
  67                                             &cls_mall);
  68         if (!err)
  69                 head->flags |= TCA_CLS_FLAGS_IN_HW;
  70
  71         return err;
  72 }
  73
  74 static void mall_destroy_hw_filter(struct tcf_proto *tp,
  75                                    struct cls_mall_head *head,
  76                                    unsigned long cookie)
  77 {
  78         struct net_device *dev = tp->q->dev_queue->dev;
  79         struct tc_cls_matchall_offload cls_mall = {};
  80
  81         tc_cls_common_offload_init(&cls_mall.common, tp);
  82         cls_mall.command = TC_CLSMATCHALL_DESTROY;
  83         cls_mall.cookie = cookie;
  84
  85         dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_CLSMATCHALL, &cls_mall);
  86 }
  87
  88 static void mall_destroy(struct tcf_proto *tp)
  89 {
  90         struct cls_mall_head *head = rtnl_dereference(tp->root);
  91         struct net_device *dev = tp->q->dev_queue->dev;
  92
  93         if (!head)
  94                 return;
  95
  96         if (tc_should_offload(dev, head->flags))
  97                 mall_destroy_hw_filter(tp, head, (unsigned long) head);
  98
  99         call_rcu(&head->rcu, mall_destroy_rcu);
 100 }
 101
 102 static void *mall_get(struct tcf_proto *tp, u32 handle)
 103 {
 104         return NULL;
 105 }
 106
 107 static const struct nla_policy mall_policy[TCA_MATCHALL_MAX + 1] = {
 108         [TCA_MATCHALL_UNSPEC]           = { .type = NLA_UNSPEC },
 109         [TCA_MATCHALL_CLASSID]          = { .type = NLA_U32 },
 110 };
 111
 112 static int mall_set_parms(struct net *net, struct tcf_proto *tp,
 113                           struct cls_mall_head *head,
 114                           unsigned long base, struct nlattr **tb,
 115                           struct nlattr *est, bool ovr)
 116 {
 117         int err;
 118
 119         err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr);
 120         if (err < 0)
 121                 return err;
 122
 123         if (tb[TCA_MATCHALL_CLASSID]) {
 124                 head->res.classid = nla_get_u32(tb[TCA_MATCHALL_CLASSID]);
 125                 tcf_bind_filter(tp, &head->res, base);
 126         }
 127         return 0;
 128 }
 129
 130 static int mall_change(struct net *net, struct sk_buff *in_skb,
 131                        struct tcf_proto *tp, unsigned long base,
 132                        u32 handle, struct nlattr **tca,
 133                        void **arg, bool ovr)
 134 {
 135         struct cls_mall_head *head = rtnl_dereference(tp->root);
 136         struct net_device *dev = tp->q->dev_queue->dev;
 137         struct nlattr *tb[TCA_MATCHALL_MAX + 1];
 138         struct cls_mall_head *new;
 139         u32 flags = 0;
 140         int err;
 141
 142         if (!tca[TCA_OPTIONS])
 143                 return -EINVAL;
 144
 145         if (head)
 146                 return -EEXIST;
 147
 148         err = nla_parse_nested(tb, TCA_MATCHALL_MAX, tca[TCA_OPTIONS],
 149                                mall_policy, NULL);
 150         if (err < 0)
 151                 return err;
 152
 153         if (tb[TCA_MATCHALL_FLAGS]) {
 154                 flags = nla_get_u32(tb[TCA_MATCHALL_FLAGS]);
 155                 if (!tc_flags_valid(flags))
 156                         return -EINVAL;
 157         }
 158
 159         new = kzalloc(sizeof(*new), GFP_KERNEL);
 160         if (!new)
 161                 return -ENOBUFS;
 162
 163         err = tcf_exts_init(&new->exts, TCA_MATCHALL_ACT, 0);
 164         if (err)
 165                 goto err_exts_init;
 166
 167         if (!handle)
 168                 handle = 1;
 169         new->handle = handle;
 170         new->flags = flags;
 171
 172         err = mall_set_parms(net, tp, new, base, tb, tca[TCA_RATE], ovr);
 173         if (err)
 174                 goto err_set_parms;
 175
 176         if (tc_should_offload(dev, flags)) {
 177                 err = mall_replace_hw_filter(tp, new, (unsigned long) new);
 178                 if (err) {
 179                         if (tc_skip_sw(flags))
 180                                 goto err_replace_hw_filter;
 181                         else
 182                                 err = 0;
 183                 }
 184         }
 185
 186         if (!tc_in_hw(new->flags))
 187                 new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
 188
 189         *arg = head;
 190         rcu_assign_pointer(tp->root, new);
 191         return 0;
 192
 193 err_replace_hw_filter:
 194 err_set_parms:
 195         tcf_exts_destroy(&new->exts);
 196 err_exts_init:
 197         kfree(new);
 198         return err;
 199 }
 200
 201 static int mall_delete(struct tcf_proto *tp, void *arg, bool *last)
 202 {
 203         return -EOPNOTSUPP;
 204 }
 205
 206 static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 207 {
 208         struct cls_mall_head *head = rtnl_dereference(tp->root);
 209
 210         if (arg->count < arg->skip)
 211                 goto skip;
 212         if (arg->fn(tp, head, arg) < 0)
 213                 arg->stop = 1;
 214 skip:
 215         arg->count++;
 216 }
 217
 218 static int mall_dump(struct net *net, struct tcf_proto *tp, void *fh,
 219                      struct sk_buff *skb, struct tcmsg *t)
 220 {
 221         struct cls_mall_head *head = fh;
 222         struct nlattr *nest;
 223
 224         if (!head)
 225                 return skb->len;
 226
 227         t->tcm_handle = head->handle;
 228
 229         nest = nla_nest_start(skb, TCA_OPTIONS);
 230         if (!nest)
 231                 goto nla_put_failure;
 232
 233         if (head->res.classid &&
 234             nla_put_u32(skb, TCA_MATCHALL_CLASSID, head->res.classid))
 235                 goto nla_put_failure;
 236
 237         if (head->flags && nla_put_u32(skb, TCA_MATCHALL_FLAGS, head->flags))
 238                 goto nla_put_failure;
 239
 240         if (tcf_exts_dump(skb, &head->exts))
 241                 goto nla_put_failure;
 242
 243         nla_nest_end(skb, nest);
 244
 245         if (tcf_exts_dump_stats(skb, &head->exts) < 0)
 246                 goto nla_put_failure;
 247
 248         return skb->len;
 249
 250 nla_put_failure:
 251         nla_nest_cancel(skb, nest);
 252         return -1;
 253 }
 254
 255 static void mall_bind_class(void *fh, u32 classid, unsigned long cl)
 256 {
 257         struct cls_mall_head *head = fh;
 258
 259         if (head && head->res.classid == classid)
 260                 head->res.class = cl;
 261 }
 262
 263 static struct tcf_proto_ops cls_mall_ops __read_mostly = {
 264         .kind           = "matchall",
 265         .classify       = mall_classify,
 266         .init           = mall_init,
 267         .destroy        = mall_destroy,
 268         .get            = mall_get,
 269         .change         = mall_change,
 270         .delete         = mall_delete,
 271         .walk           = mall_walk,
 272         .dump           = mall_dump,
 273         .bind_class     = mall_bind_class,
 274         .owner          = THIS_MODULE,
 275 };
 276
 277 static int __init cls_mall_init(void)
 278 {
 279         return register_tcf_proto_ops(&cls_mall_ops);
 280 }
 281
 282 static void __exit cls_mall_exit(void)
 283 {
 284         unregister_tcf_proto_ops(&cls_mall_ops);
 285 }
 286
 287 module_init(cls_mall_init);
 288 module_exit(cls_mall_exit);
 289
 290 MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
 291 MODULE_DESCRIPTION("Match-all classifier");
 292 MODULE_LICENSE("GPL v2");