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