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