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root/net/sched/cls_fw.c

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DEFINITIONS

This source file includes following definitions.
  1. fw_hash
  2. fw_classify
  3. fw_get
  4. fw_put
  5. fw_init
  6. fw_delete_filter
  7. fw_destroy
  8. fw_delete
  9. fw_change_attrs
  10. fw_change
  11. fw_walk
  12. fw_dump
  13. init_fw
  14. exit_fw

/*
 * net/sched/cls_fw.c   Classifier mapping ipchains' fwmark to traffic class.
 *
 *              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:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 * Changes:
 * Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_walk off by one
 * Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_delete killed all the filter (and kernel).
 * Alex <alex@pilotsoft.com> : 2004xxyy: Added Action extension
 *
 * JHS: We should remove the CONFIG_NET_CLS_IND from here
 * eventually when the meta match extension is made available
 *
 */

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

#define HTSIZE (PAGE_SIZE/sizeof(struct fw_filter *))

struct fw_head
{
        struct fw_filter *ht[HTSIZE];
        u32 mask;
};

struct fw_filter
{
        struct fw_filter        *next;
        u32                     id;
        struct tcf_result       res;
#ifdef CONFIG_NET_CLS_IND
        char                    indev[IFNAMSIZ];
#endif /* CONFIG_NET_CLS_IND */
        struct tcf_exts         exts;
};

static const struct tcf_ext_map fw_ext_map = {
        .action = TCA_FW_ACT,
        .police = TCA_FW_POLICE
};

static __inline__ int fw_hash(u32 handle)
{
        if (HTSIZE == 4096)
                return ((handle >> 24) & 0xFFF) ^
                       ((handle >> 12) & 0xFFF) ^
                       (handle & 0xFFF);
        else if (HTSIZE == 2048)
                return ((handle >> 22) & 0x7FF) ^
                       ((handle >> 11) & 0x7FF) ^
                       (handle & 0x7FF);
        else if (HTSIZE == 1024)
                return ((handle >> 20) & 0x3FF) ^
                       ((handle >> 10) & 0x3FF) ^
                       (handle & 0x3FF);
        else if (HTSIZE == 512)
                return (handle >> 27) ^
                       ((handle >> 18) & 0x1FF) ^
                       ((handle >> 9) & 0x1FF) ^
                       (handle & 0x1FF);
        else if (HTSIZE == 256) {
                u8 *t = (u8 *) &handle;
                return t[0] ^ t[1] ^ t[2] ^ t[3];
        } else
                return handle & (HTSIZE - 1);
}

static int fw_classify(struct sk_buff *skb, struct tcf_proto *tp,
                          struct tcf_result *res)
{
        struct fw_head *head = (struct fw_head*)tp->root;
        struct fw_filter *f;
        int r;
        u32 id = skb->mark;

        if (head != NULL) {
                id &= head->mask;
                for (f=head->ht[fw_hash(id)]; f; f=f->next) {
                        if (f->id == id) {
                                *res = f->res;
#ifdef CONFIG_NET_CLS_IND
                                if (!tcf_match_indev(skb, f->indev))
                                        continue;
#endif /* CONFIG_NET_CLS_IND */
                                r = tcf_exts_exec(skb, &f->exts, res);
                                if (r < 0)
                                        continue;

                                return r;
                        }
                }
        } else {
                /* old method */
                if (id && (TC_H_MAJ(id) == 0 || !(TC_H_MAJ(id^tp->q->handle)))) {
                        res->classid = id;
                        res->class = 0;
                        return 0;
                }
        }

        return -1;
}

static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
{
        struct fw_head *head = (struct fw_head*)tp->root;
        struct fw_filter *f;

        if (head == NULL)
                return 0;

        for (f=head->ht[fw_hash(handle)]; f; f=f->next) {
                if (f->id == handle)
                        return (unsigned long)f;
        }
        return 0;
}

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

static int fw_init(struct tcf_proto *tp)
{
        return 0;
}

static inline void
fw_delete_filter(struct tcf_proto *tp, struct fw_filter *f)
{
        tcf_unbind_filter(tp, &f->res);
        tcf_exts_destroy(tp, &f->exts);
        kfree(f);
}

static void fw_destroy(struct tcf_proto *tp)
{
        struct fw_head *head = (struct fw_head*)xchg(&tp->root, NULL);
        struct fw_filter *f;
        int h;

        if (head == NULL)
                return;

        for (h=0; h<HTSIZE; h++) {
                while ((f=head->ht[h]) != NULL) {
                        head->ht[h] = f->next;
                        fw_delete_filter(tp, f);
                }
        }
        kfree(head);
}

static int fw_delete(struct tcf_proto *tp, unsigned long arg)
{
        struct fw_head *head = (struct fw_head*)tp->root;
        struct fw_filter *f = (struct fw_filter*)arg;
        struct fw_filter **fp;

        if (head == NULL || f == NULL)
                goto out;

        for (fp=&head->ht[fw_hash(f->id)]; *fp; fp = &(*fp)->next) {
                if (*fp == f) {
                        tcf_tree_lock(tp);
                        *fp = f->next;
                        tcf_tree_unlock(tp);
                        fw_delete_filter(tp, f);
                        return 0;
                }
        }
out:
        return -EINVAL;
}

static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
        [TCA_FW_CLASSID]        = { .type = NLA_U32 },
        [TCA_FW_INDEV]          = { .type = NLA_STRING, .len = IFNAMSIZ },
        [TCA_FW_MASK]           = { .type = NLA_U32 },
};

static int
fw_change_attrs(struct tcf_proto *tp, struct fw_filter *f,
        struct nlattr **tb, struct nlattr **tca, unsigned long base)
{
        struct fw_head *head = (struct fw_head *)tp->root;
        struct tcf_exts e;
        u32 mask;
        int err;

        err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &fw_ext_map);
        if (err < 0)
                return err;

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

#ifdef CONFIG_NET_CLS_IND
        if (tb[TCA_FW_INDEV]) {
                err = tcf_change_indev(tp, f->indev, tb[TCA_FW_INDEV]);
                if (err < 0)
                        goto errout;
        }
#endif /* CONFIG_NET_CLS_IND */

        if (tb[TCA_FW_MASK]) {
                mask = nla_get_u32(tb[TCA_FW_MASK]);
                if (mask != head->mask)
                        goto errout;
        } else if (head->mask != 0xFFFFFFFF)
                goto errout;

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

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

static int fw_change(struct tcf_proto *tp, unsigned long base,
                     u32 handle,
                     struct nlattr **tca,
                     unsigned long *arg)
{
        struct fw_head *head = (struct fw_head*)tp->root;
        struct fw_filter *f = (struct fw_filter *) *arg;
        struct nlattr *opt = tca[TCA_OPTIONS];
        struct nlattr *tb[TCA_FW_MAX + 1];
        int err;

        if (!opt)
                return handle ? -EINVAL : 0;

        err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
        if (err < 0)
                return err;

        if (f != NULL) {
                if (f->id != handle && handle)
                        return -EINVAL;
                return fw_change_attrs(tp, f, tb, tca, base);
        }

        if (!handle)
                return -EINVAL;

        if (head == NULL) {
                u32 mask = 0xFFFFFFFF;
                if (tb[TCA_FW_MASK])
                        mask = nla_get_u32(tb[TCA_FW_MASK]);

                head = kzalloc(sizeof(struct fw_head), GFP_KERNEL);
                if (head == NULL)
                        return -ENOBUFS;
                head->mask = mask;

                tcf_tree_lock(tp);
                tp->root = head;
                tcf_tree_unlock(tp);
        }

        f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
        if (f == NULL)
                return -ENOBUFS;

        f->id = handle;

        err = fw_change_attrs(tp, f, tb, tca, base);
        if (err < 0)
                goto errout;

        f->next = head->ht[fw_hash(handle)];
        tcf_tree_lock(tp);
        head->ht[fw_hash(handle)] = f;
        tcf_tree_unlock(tp);

        *arg = (unsigned long)f;
        return 0;

errout:
        kfree(f);
        return err;
}

static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
{
        struct fw_head *head = (struct fw_head*)tp->root;
        int h;

        if (head == NULL)
                arg->stop = 1;

        if (arg->stop)
                return;

        for (h = 0; h < HTSIZE; h++) {
                struct fw_filter *f;

                for (f = head->ht[h]; f; f = f->next) {
                        if (arg->count < arg->skip) {
                                arg->count++;
                                continue;
                        }
                        if (arg->fn(tp, (unsigned long)f, arg) < 0) {
                                arg->stop = 1;
                                return;
                        }
                        arg->count++;
                }
        }
}

static int fw_dump(struct tcf_proto *tp, unsigned long fh,
                   struct sk_buff *skb, struct tcmsg *t)
{
        struct fw_head *head = (struct fw_head *)tp->root;
        struct fw_filter *f = (struct fw_filter*)fh;
        unsigned char *b = skb_tail_pointer(skb);
        struct nlattr *nest;

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

        t->tcm_handle = f->id;

        if (!f->res.classid && !tcf_exts_is_available(&f->exts))
                return skb->len;

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

        if (f->res.classid)
                NLA_PUT_U32(skb, TCA_FW_CLASSID, f->res.classid);
#ifdef CONFIG_NET_CLS_IND
        if (strlen(f->indev))
                NLA_PUT_STRING(skb, TCA_FW_INDEV, f->indev);
#endif /* CONFIG_NET_CLS_IND */
        if (head->mask != 0xFFFFFFFF)
                NLA_PUT_U32(skb, TCA_FW_MASK, head->mask);

        if (tcf_exts_dump(skb, &f->exts, &fw_ext_map) < 0)
                goto nla_put_failure;

        nla_nest_end(skb, nest);

        if (tcf_exts_dump_stats(skb, &f->exts, &fw_ext_map) < 0)
                goto nla_put_failure;

        return skb->len;

nla_put_failure:
        nlmsg_trim(skb, b);
        return -1;
}

static struct tcf_proto_ops cls_fw_ops __read_mostly = {
        .kind           =       "fw",
        .classify       =       fw_classify,
        .init           =       fw_init,
        .destroy        =       fw_destroy,
        .get            =       fw_get,
        .put            =       fw_put,
        .change         =       fw_change,
        .delete         =       fw_delete,
        .walk           =       fw_walk,
        .dump           =       fw_dump,
        .owner          =       THIS_MODULE,
};

static int __init init_fw(void)
{
        return register_tcf_proto_ops(&cls_fw_ops);
}

static void __exit exit_fw(void)
{
        unregister_tcf_proto_ops(&cls_fw_ops);
}

module_init(init_fw)
module_exit(exit_fw)
MODULE_LICENSE("GPL");

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