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_filter {
  20         struct tcf_exts exts;
  21         struct tcf_result res;
  22         u32 handle;
  23         struct rcu_head rcu;
  24         u32 flags;
  25 };
  26
  27 struct cls_mall_head {
  28         struct cls_mall_filter *filter;
  29         struct rcu_head rcu;
  30 };
  31
  32 static int mall_classify(struct sk_buff *skb, const struct tcf_proto *tp,
  33                          struct tcf_result *res)
  34 {
  35         struct cls_mall_head *head = rcu_dereference_bh(tp->root);
  36         struct cls_mall_filter *f = head->filter;
  37
  38         if (tc_skip_sw(f->flags))
  39                 return -1;
  40
  41         return tcf_exts_exec(skb, &f->exts, res);
  42 }
  43
  44 static int mall_init(struct tcf_proto *tp)
  45 {
  46         struct cls_mall_head *head;
  47
  48         head = kzalloc(sizeof(*head), GFP_KERNEL);
  49         if (!head)
  50                 return -ENOBUFS;
  51
  52         rcu_assign_pointer(tp->root, head);
  53
  54         return 0;
  55 }
  56
  57 static void mall_destroy_filter(struct rcu_head *head)
  58 {
  59         struct cls_mall_filter *f = container_of(head, struct cls_mall_filter, rcu);
  60
  61         tcf_exts_destroy(&f->exts);
  62
  63         kfree(f);
  64 }
  65
  66 static int mall_replace_hw_filter(struct tcf_proto *tp,
  67                                   struct cls_mall_filter *f,
  68                                   unsigned long cookie)
  69 {
  70         struct net_device *dev = tp->q->dev_queue->dev;
  71         struct tc_to_netdev offload;
  72         struct tc_cls_matchall_offload mall_offload = {0};
  73
  74         offload.type = TC_SETUP_MATCHALL;
  75         offload.cls_mall = &mall_offload;
  76         offload.cls_mall->command = TC_CLSMATCHALL_REPLACE;
  77         offload.cls_mall->exts = &f->exts;
  78         offload.cls_mall->cookie = cookie;
  79
  80         return dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle, tp->protocol,
  81                                              &offload);
  82 }
  83
  84 static void mall_destroy_hw_filter(struct tcf_proto *tp,
  85                                    struct cls_mall_filter *f,
  86                                    unsigned long cookie)
  87 {
  88         struct net_device *dev = tp->q->dev_queue->dev;
  89         struct tc_to_netdev offload;
  90         struct tc_cls_matchall_offload mall_offload = {0};
  91
  92         offload.type = TC_SETUP_MATCHALL;
  93         offload.cls_mall = &mall_offload;
  94         offload.cls_mall->command = TC_CLSMATCHALL_DESTROY;
  95         offload.cls_mall->exts = NULL;
  96         offload.cls_mall->cookie = cookie;
  97
  98         dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle, tp->protocol,
  99                                              &offload);
 100 }
 101
 102 static bool mall_destroy(struct tcf_proto *tp, bool force)
 103 {
 104         struct cls_mall_head *head = rtnl_dereference(tp->root);
 105         struct net_device *dev = tp->q->dev_queue->dev;
 106         struct cls_mall_filter *f = head->filter;
 107
 108         if (!force && f)
 109                 return false;
 110
 111         if (f) {
 112                 if (tc_should_offload(dev, tp, f->flags))
 113                         mall_destroy_hw_filter(tp, f, (unsigned long) f);
 114
 115                 call_rcu(&f->rcu, mall_destroy_filter);
 116         }
 117         RCU_INIT_POINTER(tp->root, NULL);
 118         kfree_rcu(head, rcu);
 119         return true;
 120 }
 121
 122 static unsigned long mall_get(struct tcf_proto *tp, u32 handle)
 123 {
 124         struct cls_mall_head *head = rtnl_dereference(tp->root);
 125         struct cls_mall_filter *f = head->filter;
 126
 127         if (f && f->handle == handle)
 128                 return (unsigned long) f;
 129         return 0;
 130 }
 131
 132 static const struct nla_policy mall_policy[TCA_MATCHALL_MAX + 1] = {
 133         [TCA_MATCHALL_UNSPEC]           = { .type = NLA_UNSPEC },
 134         [TCA_MATCHALL_CLASSID]          = { .type = NLA_U32 },
 135 };
 136
 137 static int mall_set_parms(struct net *net, struct tcf_proto *tp,
 138                           struct cls_mall_filter *f,
 139                           unsigned long base, struct nlattr **tb,
 140                           struct nlattr *est, bool ovr)
 141 {
 142         struct tcf_exts e;
 143         int err;
 144
 145         tcf_exts_init(&e, TCA_MATCHALL_ACT, 0);
 146         err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
 147         if (err < 0)
 148                 return err;
 149
 150         if (tb[TCA_MATCHALL_CLASSID]) {
 151                 f->res.classid = nla_get_u32(tb[TCA_MATCHALL_CLASSID]);
 152                 tcf_bind_filter(tp, &f->res, base);
 153         }
 154
 155         tcf_exts_change(tp, &f->exts, &e);
 156
 157         return 0;
 158 }
 159
 160 static int mall_change(struct net *net, struct sk_buff *in_skb,
 161                        struct tcf_proto *tp, unsigned long base,
 162                        u32 handle, struct nlattr **tca,
 163                        unsigned long *arg, bool ovr)
 164 {
 165         struct cls_mall_head *head = rtnl_dereference(tp->root);
 166         struct cls_mall_filter *fold = (struct cls_mall_filter *) *arg;
 167         struct net_device *dev = tp->q->dev_queue->dev;
 168         struct cls_mall_filter *f;
 169         struct nlattr *tb[TCA_MATCHALL_MAX + 1];
 170         u32 flags = 0;
 171         int err;
 172
 173         if (!tca[TCA_OPTIONS])
 174                 return -EINVAL;
 175
 176         if (head->filter)
 177                 return -EBUSY;
 178
 179         if (fold)
 180                 return -EINVAL;
 181
 182         err = nla_parse_nested(tb, TCA_MATCHALL_MAX,
 183                                tca[TCA_OPTIONS], mall_policy);
 184         if (err < 0)
 185                 return err;
 186
 187         if (tb[TCA_MATCHALL_FLAGS]) {
 188                 flags = nla_get_u32(tb[TCA_MATCHALL_FLAGS]);
 189                 if (!tc_flags_valid(flags))
 190                         return -EINVAL;
 191         }
 192
 193         f = kzalloc(sizeof(*f), GFP_KERNEL);
 194         if (!f)
 195                 return -ENOBUFS;
 196
 197         tcf_exts_init(&f->exts, TCA_MATCHALL_ACT, 0);
 198
 199         if (!handle)
 200                 handle = 1;
 201         f->handle = handle;
 202         f->flags = flags;
 203
 204         err = mall_set_parms(net, tp, f, base, tb, tca[TCA_RATE], ovr);
 205         if (err)
 206                 goto errout;
 207
 208         if (tc_should_offload(dev, tp, flags)) {
 209                 err = mall_replace_hw_filter(tp, f, (unsigned long) f);
 210                 if (err) {
 211                         if (tc_skip_sw(flags))
 212                                 goto errout;
 213                         else
 214                                 err = 0;
 215                 }
 216         }
 217
 218         *arg = (unsigned long) f;
 219         rcu_assign_pointer(head->filter, f);
 220
 221         return 0;
 222
 223 errout:
 224         kfree(f);
 225         return err;
 226 }
 227
 228 static int mall_delete(struct tcf_proto *tp, unsigned long arg)
 229 {
 230         struct cls_mall_head *head = rtnl_dereference(tp->root);
 231         struct cls_mall_filter *f = (struct cls_mall_filter *) arg;
 232         struct net_device *dev = tp->q->dev_queue->dev;
 233
 234         if (tc_should_offload(dev, tp, f->flags))
 235                 mall_destroy_hw_filter(tp, f, (unsigned long) f);
 236
 237         RCU_INIT_POINTER(head->filter, NULL);
 238         tcf_unbind_filter(tp, &f->res);
 239         call_rcu(&f->rcu, mall_destroy_filter);
 240         return 0;
 241 }
 242
 243 static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 244 {
 245         struct cls_mall_head *head = rtnl_dereference(tp->root);
 246         struct cls_mall_filter *f = head->filter;
 247
 248         if (arg->count < arg->skip)
 249                 goto skip;
 250         if (arg->fn(tp, (unsigned long) f, arg) < 0)
 251                 arg->stop = 1;
 252 skip:
 253         arg->count++;
 254 }
 255
 256 static int mall_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
 257                      struct sk_buff *skb, struct tcmsg *t)
 258 {
 259         struct cls_mall_filter *f = (struct cls_mall_filter *) fh;
 260         struct nlattr *nest;
 261
 262         if (!f)
 263                 return skb->len;
 264
 265         t->tcm_handle = f->handle;
 266
 267         nest = nla_nest_start(skb, TCA_OPTIONS);
 268         if (!nest)
 269                 goto nla_put_failure;
 270
 271         if (f->res.classid &&
 272             nla_put_u32(skb, TCA_MATCHALL_CLASSID, f->res.classid))
 273                 goto nla_put_failure;
 274
 275         if (tcf_exts_dump(skb, &f->exts))
 276                 goto nla_put_failure;
 277
 278         nla_nest_end(skb, nest);
 279
 280         if (tcf_exts_dump_stats(skb, &f->exts) < 0)
 281                 goto nla_put_failure;
 282
 283         return skb->len;
 284
 285 nla_put_failure:
 286         nla_nest_cancel(skb, nest);
 287         return -1;
 288 }
 289
 290 static struct tcf_proto_ops cls_mall_ops __read_mostly = {
 291         .kind           = "matchall",
 292         .classify       = mall_classify,
 293         .init           = mall_init,
 294         .destroy        = mall_destroy,
 295         .get            = mall_get,
 296         .change         = mall_change,
 297         .delete         = mall_delete,
 298         .walk           = mall_walk,
 299         .dump           = mall_dump,
 300         .owner          = THIS_MODULE,
 301 };
 302
 303 static int __init cls_mall_init(void)
 304 {
 305         return register_tcf_proto_ops(&cls_mall_ops);
 306 }
 307
 308 static void __exit cls_mall_exit(void)
 309 {
 310         unregister_tcf_proto_ops(&cls_mall_ops);
 311 }
 312
 313 module_init(cls_mall_init);
 314 module_exit(cls_mall_exit);
 315
 316 MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
 317 MODULE_DESCRIPTION("Match-all classifier");
 318 MODULE_LICENSE("GPL v2");