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