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