dn_rules.c
/*
* 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 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 = { .fld_dst = 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 fib_rule_hdr *frh)
{
struct dn_fib_rule *r = (struct dn_fib_rule *)rule;
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 void dn_fib_rule_flush_cache(struct fib_rules_ops *ops)
{
dn_rt_cache_flush(-1);
}
static const struct fib_rules_ops __net_initdata dn_fib_rules_ops_template = {
.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 = fib_default_rule_pref,
.flush_cache = dn_fib_rule_flush_cache,
.nlgroup = RTNLGRP_DECnet_RULE,
.policy = dn_fib_rule_policy,
.owner = THIS_MODULE,
.fro_net = &init_net,
};
void __init dn_fib_rules_init(void)
{
dn_fib_rules_ops =
fib_rules_register(&dn_fib_rules_ops_template, &init_net);
BUG_ON(IS_ERR(dn_fib_rules_ops));
BUG_ON(fib_default_rule_add(dn_fib_rules_ops, 0x7fff,
RT_TABLE_MAIN, 0));
}
void __exit dn_fib_rules_cleanup(void)
{
fib_rules_unregister(dn_fib_rules_ops);
rcu_barrier();
}