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