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         kfree_rcu(head, rcu);
 118         return true;
 119 }
 120
 121 static unsigned long mall_get(struct tcf_proto *tp, u32 handle)
 122 {
 123         struct cls_mall_head *head = rtnl_dereference(tp->root);
 124         struct cls_mall_filter *f = head->filter;
 125
 126         if (f && f->handle == handle)
 127                 return (unsigned long) f;
 128         return 0;
 129 }
 130
 131 static const struct nla_policy mall_policy[TCA_MATCHALL_MAX + 1] = {
 132         [TCA_MATCHALL_UNSPEC]           = { .type = NLA_UNSPEC },
 133         [TCA_MATCHALL_CLASSID]          = { .type = NLA_U32 },
 134 };
 135
 136 static int mall_set_parms(struct net *net, struct tcf_proto *tp,
 137                           struct cls_mall_filter *f,
 138                           unsigned long base, struct nlattr **tb,
 139                           struct nlattr *est, bool ovr)
 140 {
 141         struct tcf_exts e;
 142         int err;
 143
 144         tcf_exts_init(&e, TCA_MATCHALL_ACT, 0);
 145         err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
 146         if (err < 0)
 147                 return err;
 148
 149         if (tb[TCA_MATCHALL_CLASSID]) {
 150                 f->res.classid = nla_get_u32(tb[TCA_MATCHALL_CLASSID]);
 151                 tcf_bind_filter(tp, &f->res, base);
 152         }
 153
 154         tcf_exts_change(tp, &f->exts, &e);
 155
 156         return 0;
 157 }
 158
 159 static int mall_change(struct net *net, struct sk_buff *in_skb,
 160                        struct tcf_proto *tp, unsigned long base,
 161                        u32 handle, struct nlattr **tca,
 162                        unsigned long *arg, bool ovr)
 163 {
 164         struct cls_mall_head *head = rtnl_dereference(tp->root);
 165         struct cls_mall_filter *fold = (struct cls_mall_filter *) *arg;
 166         struct net_device *dev = tp->q->dev_queue->dev;
 167         struct cls_mall_filter *f;
 168         struct nlattr *tb[TCA_MATCHALL_MAX + 1];
 169         u32 flags = 0;
 170         int err;
 171
 172         if (!tca[TCA_OPTIONS])
 173                 return -EINVAL;
 174
 175         if (head->filter)
 176                 return -EBUSY;
 177
 178         if (fold)
 179                 return -EINVAL;
 180
 181         err = nla_parse_nested(tb, TCA_MATCHALL_MAX,
 182                                tca[TCA_OPTIONS], mall_policy);
 183         if (err < 0)
 184                 return err;
 185
 186         if (tb[TCA_MATCHALL_FLAGS]) {
 187                 flags = nla_get_u32(tb[TCA_MATCHALL_FLAGS]);
 188                 if (!tc_flags_valid(flags))
 189                         return -EINVAL;
 190         }
 191
 192         f = kzalloc(sizeof(*f), GFP_KERNEL);
 193         if (!f)
 194                 return -ENOBUFS;
 195
 196         tcf_exts_init(&f->exts, TCA_MATCHALL_ACT, 0);
 197
 198         if (!handle)
 199                 handle = 1;
 200         f->handle = handle;
 201         f->flags = flags;
 202
 203         err = mall_set_parms(net, tp, f, base, tb, tca[TCA_RATE], ovr);
 204         if (err)
 205                 goto errout;
 206
 207         if (tc_should_offload(dev, tp, flags)) {
 208                 err = mall_replace_hw_filter(tp, f, (unsigned long) f);
 209                 if (err) {
 210                         if (tc_skip_sw(flags))
 211                                 goto errout;
 212                         else
 213                                 err = 0;
 214                 }
 215         }
 216
 217         *arg = (unsigned long) f;
 218         rcu_assign_pointer(head->filter, f);
 219
 220         return 0;
 221
 222 errout:
 223         kfree(f);
 224         return err;
 225 }
 226
 227 static int mall_delete(struct tcf_proto *tp, unsigned long arg)
 228 {
 229         struct cls_mall_head *head = rtnl_dereference(tp->root);
 230         struct cls_mall_filter *f = (struct cls_mall_filter *) arg;
 231         struct net_device *dev = tp->q->dev_queue->dev;
 232
 233         if (tc_should_offload(dev, tp, f->flags))
 234                 mall_destroy_hw_filter(tp, f, (unsigned long) f);
 235
 236         RCU_INIT_POINTER(head->filter, NULL);
 237         tcf_unbind_filter(tp, &f->res);
 238         call_rcu(&f->rcu, mall_destroy_filter);
 239         return 0;
 240 }
 241
 242 static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 243 {
 244         struct cls_mall_head *head = rtnl_dereference(tp->root);
 245         struct cls_mall_filter *f = head->filter;
 246
 247         if (arg->count < arg->skip)
 248                 goto skip;
 249         if (arg->fn(tp, (unsigned long) f, arg) < 0)
 250                 arg->stop = 1;
 251 skip:
 252         arg->count++;
 253 }
 254
 255 static int mall_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
 256                      struct sk_buff *skb, struct tcmsg *t)
 257 {
 258         struct cls_mall_filter *f = (struct cls_mall_filter *) fh;
 259         struct nlattr *nest;
 260
 261         if (!f)
 262                 return skb->len;
 263
 264         t->tcm_handle = f->handle;
 265
 266         nest = nla_nest_start(skb, TCA_OPTIONS);
 267         if (!nest)
 268                 goto nla_put_failure;
 269
 270         if (f->res.classid &&
 271             nla_put_u32(skb, TCA_MATCHALL_CLASSID, f->res.classid))
 272                 goto nla_put_failure;
 273
 274         if (tcf_exts_dump(skb, &f->exts))
 275                 goto nla_put_failure;
 276
 277         nla_nest_end(skb, nest);
 278
 279         if (tcf_exts_dump_stats(skb, &f->exts) < 0)
 280                 goto nla_put_failure;
 281
 282         return skb->len;
 283
 284 nla_put_failure:
 285         nla_nest_cancel(skb, nest);
 286         return -1;
 287 }
 288
 289 static struct tcf_proto_ops cls_mall_ops __read_mostly = {
 290         .kind           = "matchall",
 291         .classify       = mall_classify,
 292         .init           = mall_init,
 293         .destroy        = mall_destroy,
 294         .get            = mall_get,
 295         .change         = mall_change,
 296         .delete         = mall_delete,
 297         .walk           = mall_walk,
 298         .dump           = mall_dump,
 299         .owner          = THIS_MODULE,
 300 };
 301
 302 static int __init cls_mall_init(void)
 303 {
 304         return register_tcf_proto_ops(&cls_mall_ops);
 305 }
 306
 307 static void __exit cls_mall_exit(void)
 308 {
 309         unregister_tcf_proto_ops(&cls_mall_ops);
 310 }
 311
 312 module_init(cls_mall_init);
 313 module_exit(cls_mall_exit);
 314
 315 MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
 316 MODULE_DESCRIPTION("Match-all classifier");
 317 MODULE_LICENSE("GPL v2");