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, NULL);
  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         tcf_block_offload_dec(block, &head->flags);
  85 }
  86
  87 static int mall_replace_hw_filter(struct tcf_proto *tp,
  88                                   struct cls_mall_head *head,
  89                                   unsigned long cookie,
  90                                   struct netlink_ext_ack *extack)
  91 {
  92         struct tc_cls_matchall_offload cls_mall = {};
  93         struct tcf_block *block = tp->chain->block;
  94         bool skip_sw = tc_skip_sw(head->flags);
  95         int err;
  96
  97         tc_cls_common_offload_init(&cls_mall.common, tp, extack);
  98         cls_mall.command = TC_CLSMATCHALL_REPLACE;
  99         cls_mall.exts = &head->exts;
 100         cls_mall.cookie = cookie;
 101
 102         err = tc_setup_cb_call(block, NULL, TC_SETUP_CLSMATCHALL,
 103                                &cls_mall, skip_sw);
 104         if (err < 0) {
 105                 mall_destroy_hw_filter(tp, head, cookie);
 106                 return err;
 107         } else if (err > 0) {
 108                 tcf_block_offload_inc(block, &head->flags);
 109         }
 110
 111         if (skip_sw && !(head->flags & TCA_CLS_FLAGS_IN_HW))
 112                 return -EINVAL;
 113
 114         return 0;
 115 }
 116
 117 static void mall_destroy(struct tcf_proto *tp)
 118 {
 119         struct cls_mall_head *head = rtnl_dereference(tp->root);
 120
 121         if (!head)
 122                 return;
 123
 124         if (!tc_skip_hw(head->flags))
 125                 mall_destroy_hw_filter(tp, head, (unsigned long) head);
 126
 127         if (tcf_exts_get_net(&head->exts))
 128                 call_rcu(&head->rcu, mall_destroy_rcu);
 129         else
 130                 __mall_destroy(head);
 131 }
 132
 133 static void *mall_get(struct tcf_proto *tp, u32 handle)
 134 {
 135         return NULL;
 136 }
 137
 138 static const struct nla_policy mall_policy[TCA_MATCHALL_MAX + 1] = {
 139         [TCA_MATCHALL_UNSPEC]           = { .type = NLA_UNSPEC },
 140         [TCA_MATCHALL_CLASSID]          = { .type = NLA_U32 },
 141 };
 142
 143 static int mall_set_parms(struct net *net, struct tcf_proto *tp,
 144                           struct cls_mall_head *head,
 145                           unsigned long base, struct nlattr **tb,
 146                           struct nlattr *est, bool ovr,
 147                           struct netlink_ext_ack *extack)
 148 {
 149         int err;
 150
 151         err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr, extack);
 152         if (err < 0)
 153                 return err;
 154
 155         if (tb[TCA_MATCHALL_CLASSID]) {
 156                 head->res.classid = nla_get_u32(tb[TCA_MATCHALL_CLASSID]);
 157                 tcf_bind_filter(tp, &head->res, base);
 158         }
 159         return 0;
 160 }
 161
 162 static int mall_change(struct net *net, struct sk_buff *in_skb,
 163                        struct tcf_proto *tp, unsigned long base,
 164                        u32 handle, struct nlattr **tca,
 165                        void **arg, bool ovr, struct netlink_ext_ack *extack)
 166 {
 167         struct cls_mall_head *head = rtnl_dereference(tp->root);
 168         struct nlattr *tb[TCA_MATCHALL_MAX + 1];
 169         struct cls_mall_head *new;
 170         u32 flags = 0;
 171         int err;
 172
 173         if (!tca[TCA_OPTIONS])
 174                 return -EINVAL;
 175
 176         if (head)
 177                 return -EEXIST;
 178
 179         err = nla_parse_nested(tb, TCA_MATCHALL_MAX, tca[TCA_OPTIONS],
 180                                mall_policy, NULL);
 181         if (err < 0)
 182                 return err;
 183
 184         if (tb[TCA_MATCHALL_FLAGS]) {
 185                 flags = nla_get_u32(tb[TCA_MATCHALL_FLAGS]);
 186                 if (!tc_flags_valid(flags))
 187                         return -EINVAL;
 188         }
 189
 190         new = kzalloc(sizeof(*new), GFP_KERNEL);
 191         if (!new)
 192                 return -ENOBUFS;
 193
 194         err = tcf_exts_init(&new->exts, TCA_MATCHALL_ACT, 0);
 195         if (err)
 196                 goto err_exts_init;
 197
 198         if (!handle)
 199                 handle = 1;
 200         new->handle = handle;
 201         new->flags = flags;
 202
 203         err = mall_set_parms(net, tp, new, base, tb, tca[TCA_RATE], ovr,
 204                              extack);
 205         if (err)
 206                 goto err_set_parms;
 207
 208         if (!tc_skip_hw(new->flags)) {
 209                 err = mall_replace_hw_filter(tp, new, (unsigned long)new,
 210                                              extack);
 211                 if (err)
 212                         goto err_replace_hw_filter;
 213         }
 214
 215         if (!tc_in_hw(new->flags))
 216                 new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
 217
 218         *arg = head;
 219         rcu_assign_pointer(tp->root, new);
 220         return 0;
 221
 222 err_replace_hw_filter:
 223 err_set_parms:
 224         tcf_exts_destroy(&new->exts);
 225 err_exts_init:
 226         kfree(new);
 227         return err;
 228 }
 229
 230 static int mall_delete(struct tcf_proto *tp, void *arg, bool *last,
 231                        struct netlink_ext_ack *extack)
 232 {
 233         return -EOPNOTSUPP;
 234 }
 235
 236 static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 237 {
 238         struct cls_mall_head *head = rtnl_dereference(tp->root);
 239
 240         if (arg->count < arg->skip)
 241                 goto skip;
 242         if (arg->fn(tp, head, arg) < 0)
 243                 arg->stop = 1;
 244 skip:
 245         arg->count++;
 246 }
 247
 248 static int mall_dump(struct net *net, struct tcf_proto *tp, void *fh,
 249                      struct sk_buff *skb, struct tcmsg *t)
 250 {
 251         struct cls_mall_head *head = fh;
 252         struct nlattr *nest;
 253
 254         if (!head)
 255                 return skb->len;
 256
 257         t->tcm_handle = head->handle;
 258
 259         nest = nla_nest_start(skb, TCA_OPTIONS);
 260         if (!nest)
 261                 goto nla_put_failure;
 262
 263         if (head->res.classid &&
 264             nla_put_u32(skb, TCA_MATCHALL_CLASSID, head->res.classid))
 265                 goto nla_put_failure;
 266
 267         if (head->flags && nla_put_u32(skb, TCA_MATCHALL_FLAGS, head->flags))
 268                 goto nla_put_failure;
 269
 270         if (tcf_exts_dump(skb, &head->exts))
 271                 goto nla_put_failure;
 272
 273         nla_nest_end(skb, nest);
 274
 275         if (tcf_exts_dump_stats(skb, &head->exts) < 0)
 276                 goto nla_put_failure;
 277
 278         return skb->len;
 279
 280 nla_put_failure:
 281         nla_nest_cancel(skb, nest);
 282         return -1;
 283 }
 284
 285 static void mall_bind_class(void *fh, u32 classid, unsigned long cl)
 286 {
 287         struct cls_mall_head *head = fh;
 288
 289         if (head && head->res.classid == classid)
 290                 head->res.class = cl;
 291 }
 292
 293 static struct tcf_proto_ops cls_mall_ops __read_mostly = {
 294         .kind           = "matchall",
 295         .classify       = mall_classify,
 296         .init           = mall_init,
 297         .destroy        = mall_destroy,
 298         .get            = mall_get,
 299         .change         = mall_change,
 300         .delete         = mall_delete,
 301         .walk           = mall_walk,
 302         .dump           = mall_dump,
 303         .bind_class     = mall_bind_class,
 304         .owner          = THIS_MODULE,
 305 };
 306
 307 static int __init cls_mall_init(void)
 308 {
 309         return register_tcf_proto_ops(&cls_mall_ops);
 310 }
 311
 312 static void __exit cls_mall_exit(void)
 313 {
 314         unregister_tcf_proto_ops(&cls_mall_ops);
 315 }
 316
 317 module_init(cls_mall_init);
 318 module_exit(cls_mall_exit);
 319
 320 MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
 321 MODULE_DESCRIPTION("Match-all classifier");
 322 MODULE_LICENSE("GPL v2");