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