[funini.com] -> [kei@sodan] -> Kernel Reading

root/net/decnet/dn_rules.c

/* [<][>][^][v][top][bottom][index][help] */

DEFINITIONS

This source file includes following definitions.
  1. dn_fib_lookup
  2. dn_fib_rule_action
  3. dn_fib_rule_match
  4. dn_fib_rule_configure
  5. dn_fib_rule_compare
  6. dnet_addr_type
  7. dn_fib_rule_fill
  8. dn_fib_rule_default_pref
  9. dn_fib_rule_flush_cache
  10. dn_fib_rules_init
  11. dn_fib_rules_cleanup


/*
 * DECnet       An implementation of the DECnet protocol suite for the LINUX
 *              operating system.  DECnet is implemented using the  BSD Socket
 *              interface as the means of communication with the user level.
 *
 *              DECnet Routing Forwarding Information Base (Rules)
 *
 * Author:      Steve Whitehouse <SteveW@ACM.org>
 *              Mostly copied from Alexey Kuznetsov's ipv4/fib_rules.c
 *
 *
 * Changes:
 *              Steve Whitehouse <steve@chygwyn.com>
 *              Updated for Thomas Graf's generic rules
 *
 */
#include <linux/net.h>
#include <linux/init.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/netdevice.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/rcupdate.h>
#include <net/neighbour.h>
#include <net/dst.h>
#include <net/flow.h>
#include <net/fib_rules.h>
#include <net/dn.h>
#include <net/dn_fib.h>
#include <net/dn_neigh.h>
#include <net/dn_dev.h>
#include <net/dn_route.h>

static struct fib_rules_ops dn_fib_rules_ops;

struct dn_fib_rule
{
        struct fib_rule         common;
        unsigned char           dst_len;
        unsigned char           src_len;
        __le16                  src;
        __le16                  srcmask;
        __le16                  dst;
        __le16                  dstmask;
        __le16                  srcmap;
        u8                      flags;
};


int dn_fib_lookup(struct flowi *flp, struct dn_fib_res *res)
{
        struct fib_lookup_arg arg = {
                .result = res,
        };
        int err;

        err = fib_rules_lookup(&dn_fib_rules_ops, flp, 0, &arg);
        res->r = arg.rule;

        return err;
}

static int dn_fib_rule_action(struct fib_rule *rule, struct flowi *flp,
                              int flags, struct fib_lookup_arg *arg)
{
        int err = -EAGAIN;
        struct dn_fib_table *tbl;

        switch(rule->action) {
        case FR_ACT_TO_TBL:
                break;

        case FR_ACT_UNREACHABLE:
                err = -ENETUNREACH;
                goto errout;

        case FR_ACT_PROHIBIT:
                err = -EACCES;
                goto errout;

        case FR_ACT_BLACKHOLE:
        default:
                err = -EINVAL;
                goto errout;
        }

        tbl = dn_fib_get_table(rule->table, 0);
        if (tbl == NULL)
                goto errout;

        err = tbl->lookup(tbl, flp, (struct dn_fib_res *)arg->result);
        if (err > 0)
                err = -EAGAIN;
errout:
        return err;
}

static const struct nla_policy dn_fib_rule_policy[FRA_MAX+1] = {
        FRA_GENERIC_POLICY,
};

static int dn_fib_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
{
        struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
        __le16 daddr = fl->fld_dst;
        __le16 saddr = fl->fld_src;

        if (((saddr ^ r->src) & r->srcmask) ||
            ((daddr ^ r->dst) & r->dstmask))
                return 0;

        return 1;
}

static int dn_fib_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
                                 struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
                                 struct nlattr **tb)
{
        int err = -EINVAL;
        struct dn_fib_rule *r = (struct dn_fib_rule *)rule;

        if (frh->tos)
                goto  errout;

        if (rule->table == RT_TABLE_UNSPEC) {
                if (rule->action == FR_ACT_TO_TBL) {
                        struct dn_fib_table *table;

                        table = dn_fib_empty_table();
                        if (table == NULL) {
                                err = -ENOBUFS;
                                goto errout;
                        }

                        rule->table = table->n;
                }
        }

        if (frh->src_len)
                r->src = nla_get_le16(tb[FRA_SRC]);

        if (frh->dst_len)
                r->dst = nla_get_le16(tb[FRA_DST]);

        r->src_len = frh->src_len;
        r->srcmask = dnet_make_mask(r->src_len);
        r->dst_len = frh->dst_len;
        r->dstmask = dnet_make_mask(r->dst_len);
        err = 0;
errout:
        return err;
}

static int dn_fib_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
                               struct nlattr **tb)
{
        struct dn_fib_rule *r = (struct dn_fib_rule *)rule;

        if (frh->src_len && (r->src_len != frh->src_len))
                return 0;

        if (frh->dst_len && (r->dst_len != frh->dst_len))
                return 0;

        if (frh->src_len && (r->src != nla_get_le16(tb[FRA_SRC])))
                return 0;

        if (frh->dst_len && (r->dst != nla_get_le16(tb[FRA_DST])))
                return 0;

        return 1;
}

unsigned dnet_addr_type(__le16 addr)
{
        struct flowi fl = { .nl_u = { .dn_u = { .daddr = addr } } };
        struct dn_fib_res res;
        unsigned ret = RTN_UNICAST;
        struct dn_fib_table *tb = dn_fib_get_table(RT_TABLE_LOCAL, 0);

        res.r = NULL;

        if (tb) {
                if (!tb->lookup(tb, &fl, &res)) {
                        ret = res.type;
                        dn_fib_res_put(&res);
                }
        }
        return ret;
}

static int dn_fib_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
                            struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
{
        struct dn_fib_rule *r = (struct dn_fib_rule *)rule;

        frh->family = AF_DECnet;
        frh->dst_len = r->dst_len;
        frh->src_len = r->src_len;
        frh->tos = 0;

        if (r->dst_len)
                NLA_PUT_LE16(skb, FRA_DST, r->dst);
        if (r->src_len)
                NLA_PUT_LE16(skb, FRA_SRC, r->src);

        return 0;

nla_put_failure:
        return -ENOBUFS;
}

static u32 dn_fib_rule_default_pref(struct fib_rules_ops *ops)
{
        struct list_head *pos;
        struct fib_rule *rule;

        if (!list_empty(&dn_fib_rules_ops.rules_list)) {
                pos = dn_fib_rules_ops.rules_list.next;
                if (pos->next != &dn_fib_rules_ops.rules_list) {
                        rule = list_entry(pos->next, struct fib_rule, list);
                        if (rule->pref)
                                return rule->pref - 1;
                }
        }

        return 0;
}

static void dn_fib_rule_flush_cache(struct fib_rules_ops *ops)
{
        dn_rt_cache_flush(-1);
}

static struct fib_rules_ops dn_fib_rules_ops = {
        .family         = AF_DECnet,
        .rule_size      = sizeof(struct dn_fib_rule),
        .addr_size      = sizeof(u16),
        .action         = dn_fib_rule_action,
        .match          = dn_fib_rule_match,
        .configure      = dn_fib_rule_configure,
        .compare        = dn_fib_rule_compare,
        .fill           = dn_fib_rule_fill,
        .default_pref   = dn_fib_rule_default_pref,
        .flush_cache    = dn_fib_rule_flush_cache,
        .nlgroup        = RTNLGRP_DECnet_RULE,
        .policy         = dn_fib_rule_policy,
        .rules_list     = LIST_HEAD_INIT(dn_fib_rules_ops.rules_list),
        .owner          = THIS_MODULE,
        .fro_net        = &init_net,
};

void __init dn_fib_rules_init(void)
{
        BUG_ON(fib_default_rule_add(&dn_fib_rules_ops, 0x7fff,
                                    RT_TABLE_MAIN, 0));
        fib_rules_register(&dn_fib_rules_ops);
}

void __exit dn_fib_rules_cleanup(void)
{
        fib_rules_unregister(&dn_fib_rules_ops);
}



/* [<][>][^][v][top][bottom][index][help] */

[funini.com] -> [kei@sodan] -> Kernel Reading