root/net/sched/cls_basic.c

DEFINITIONS

1. basic_classify
2. basic_get
3. basic_put
4. basic_init
5. basic_delete_filter
6. basic_destroy
7. basic_delete
8. basic_set_parms
9. basic_change
10. basic_walk
11. basic_dump
12. init_basic
13. exit_basic

/*
 * net/sched/cls_basic.c        Basic Packet Classifier.
 *
 *              This program is free software; you can redistribute it and/or
 *              modify it under the terms of the GNU General Public License
 *              as published by the Free Software Foundation; either version
 *              2 of the License, or (at your option) any later version.
 *
 * Authors:     Thomas Graf <tgraf@suug.ch>
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <net/netlink.h>
#include <net/act_api.h>
#include <net/pkt_cls.h>

struct basic_head
{
        u32                     hgenerator;
        struct list_head        flist;
};

struct basic_filter
{
        u32                     handle;
        struct tcf_exts         exts;
        struct tcf_ematch_tree  ematches;
        struct tcf_result       res;
        struct list_head        link;
};

static const struct tcf_ext_map basic_ext_map = {
        .action = TCA_BASIC_ACT,
        .police = TCA_BASIC_POLICE
};

static int basic_classify(struct sk_buff *skb, struct tcf_proto *tp,
                          struct tcf_result *res)
{
        int r;
        struct basic_head *head = (struct basic_head *) tp->root;
        struct basic_filter *f;

        list_for_each_entry(f, &head->flist, link) {
                if (!tcf_em_tree_match(skb, &f->ematches, NULL))
                        continue;
                *res = f->res;
                r = tcf_exts_exec(skb, &f->exts, res);
                if (r < 0)
                        continue;
                return r;
        }
        return -1;
}

static unsigned long basic_get(struct tcf_proto *tp, u32 handle)
{
        unsigned long l = 0UL;
        struct basic_head *head = (struct basic_head *) tp->root;
        struct basic_filter *f;

        if (head == NULL)
                return 0UL;

        list_for_each_entry(f, &head->flist, link)
                if (f->handle == handle)
                        l = (unsigned long) f;

        return l;
}

static void basic_put(struct tcf_proto *tp, unsigned long f)
{
}

static int basic_init(struct tcf_proto *tp)
{
        struct basic_head *head;

        head = kzalloc(sizeof(*head), GFP_KERNEL);
        if (head == NULL)
                return -ENOBUFS;
        INIT_LIST_HEAD(&head->flist);
        tp->root = head;
        return 0;
}

static inline void basic_delete_filter(struct tcf_proto *tp,
                                       struct basic_filter *f)
{
        tcf_unbind_filter(tp, &f->res);
        tcf_exts_destroy(tp, &f->exts);
        tcf_em_tree_destroy(tp, &f->ematches);
        kfree(f);
}

static void basic_destroy(struct tcf_proto *tp)
{
        struct basic_head *head = (struct basic_head *) xchg(&tp->root, NULL);
        struct basic_filter *f, *n;

        list_for_each_entry_safe(f, n, &head->flist, link) {
                list_del(&f->link);
                basic_delete_filter(tp, f);
        }
        kfree(head);
}

static int basic_delete(struct tcf_proto *tp, unsigned long arg)
{
        struct basic_head *head = (struct basic_head *) tp->root;
        struct basic_filter *t, *f = (struct basic_filter *) arg;

        list_for_each_entry(t, &head->flist, link)
                if (t == f) {
                        tcf_tree_lock(tp);
                        list_del(&t->link);
                        tcf_tree_unlock(tp);
                        basic_delete_filter(tp, t);
                        return 0;
                }

        return -ENOENT;
}

static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = {
        [TCA_BASIC_CLASSID]     = { .type = NLA_U32 },
        [TCA_BASIC_EMATCHES]    = { .type = NLA_NESTED },
};

static inline int basic_set_parms(struct tcf_proto *tp, struct basic_filter *f,
                                  unsigned long base, struct nlattr **tb,
                                  struct nlattr *est)
{
        int err = -EINVAL;
        struct tcf_exts e;
        struct tcf_ematch_tree t;

        err = tcf_exts_validate(tp, tb, est, &e, &basic_ext_map);
        if (err < 0)
                return err;

        err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &t);
        if (err < 0)
                goto errout;

        if (tb[TCA_BASIC_CLASSID]) {
                f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]);
                tcf_bind_filter(tp, &f->res, base);
        }

        tcf_exts_change(tp, &f->exts, &e);
        tcf_em_tree_change(tp, &f->ematches, &t);

        return 0;
errout:
        tcf_exts_destroy(tp, &e);
        return err;
}

static int basic_change(struct tcf_proto *tp, unsigned long base, u32 handle,
                        struct nlattr **tca, unsigned long *arg)
{
        int err;
        struct basic_head *head = (struct basic_head *) tp->root;
        struct nlattr *tb[TCA_BASIC_MAX + 1];
        struct basic_filter *f = (struct basic_filter *) *arg;

        if (tca[TCA_OPTIONS] == NULL)
                return -EINVAL;

        err = nla_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS],
                               basic_policy);
        if (err < 0)
                return err;

        if (f != NULL) {
                if (handle && f->handle != handle)
                        return -EINVAL;
                return basic_set_parms(tp, f, base, tb, tca[TCA_RATE]);
        }

        err = -ENOBUFS;
        f = kzalloc(sizeof(*f), GFP_KERNEL);
        if (f == NULL)
                goto errout;

        err = -EINVAL;
        if (handle)
                f->handle = handle;
        else {
                unsigned int i = 0x80000000;
                do {
                        if (++head->hgenerator == 0x7FFFFFFF)
                                head->hgenerator = 1;
                } while (--i > 0 && basic_get(tp, head->hgenerator));

                if (i <= 0) {
                        printk(KERN_ERR "Insufficient number of handles\n");
                        goto errout;
                }

                f->handle = head->hgenerator;
        }

        err = basic_set_parms(tp, f, base, tb, tca[TCA_RATE]);
        if (err < 0)
                goto errout;

        tcf_tree_lock(tp);
        list_add(&f->link, &head->flist);
        tcf_tree_unlock(tp);
        *arg = (unsigned long) f;

        return 0;
errout:
        if (*arg == 0UL && f)
                kfree(f);

        return err;
}

static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg)
{
        struct basic_head *head = (struct basic_head *) tp->root;
        struct basic_filter *f;

        list_for_each_entry(f, &head->flist, link) {
                if (arg->count < arg->skip)
                        goto skip;

                if (arg->fn(tp, (unsigned long) f, arg) < 0) {
                        arg->stop = 1;
                        break;
                }
skip:
                arg->count++;
        }
}

static int basic_dump(struct tcf_proto *tp, unsigned long fh,
                      struct sk_buff *skb, struct tcmsg *t)
{
        struct basic_filter *f = (struct basic_filter *) fh;
        struct nlattr *nest;

        if (f == NULL)
                return skb->len;

        t->tcm_handle = f->handle;

        nest = nla_nest_start(skb, TCA_OPTIONS);
        if (nest == NULL)
                goto nla_put_failure;

        if (f->res.classid)
                NLA_PUT_U32(skb, TCA_BASIC_CLASSID, f->res.classid);

        if (tcf_exts_dump(skb, &f->exts, &basic_ext_map) < 0 ||
            tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0)
                goto nla_put_failure;

        nla_nest_end(skb, nest);
        return skb->len;

nla_put_failure:
        nla_nest_cancel(skb, nest);
        return -1;
}

static struct tcf_proto_ops cls_basic_ops __read_mostly = {
        .kind           =       "basic",
        .classify       =       basic_classify,
        .init           =       basic_init,
        .destroy        =       basic_destroy,
        .get            =       basic_get,
        .put            =       basic_put,
        .change         =       basic_change,
        .delete         =       basic_delete,
        .walk           =       basic_walk,
        .dump           =       basic_dump,
        .owner          =       THIS_MODULE,
};

static int __init init_basic(void)
{
        return register_tcf_proto_ops(&cls_basic_ops);
}

static void __exit exit_basic(void)
{
        unregister_tcf_proto_ops(&cls_basic_ops);
}

module_init(init_basic)
module_exit(exit_basic)
MODULE_LICENSE("GPL");