linux/net/ipv6/fib6_rules.c
Patrick McHardy 25239cee7e net: rtnetlink: decouple rtnetlink address families from real address families
Decouple rtnetlink address families from real address families in socket.h to
be able to add rtnetlink interfaces to code that is not a real address family
without increasing AF_MAX/NPROTO.

This will be used to add support for multicast route dumping from all tables
as the proc interface can't be extended to support anything but the main table
without breaking compatibility.

This partialy undoes the patch to introduce independant families for routing
rules and converts ipmr routing rules to a new rtnetlink family. Similar to
that patch, values up to 127 are reserved for real address families, values
above that may be used arbitrarily.

Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-04-26 16:13:54 +02:00

306 lines
6.8 KiB
C

/*
* net/ipv6/fib6_rules.c IPv6 Routing Policy Rules
*
* Copyright (C)2003-2006 Helsinki University of Technology
* Copyright (C)2003-2006 USAGI/WIDE Project
*
* 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, version 2.
*
* Authors
* Thomas Graf <tgraf@suug.ch>
* Ville Nuorvala <vnuorval@tcs.hut.fi>
*/
#include <linux/netdevice.h>
#include <net/fib_rules.h>
#include <net/ipv6.h>
#include <net/addrconf.h>
#include <net/ip6_route.h>
#include <net/netlink.h>
struct fib6_rule
{
struct fib_rule common;
struct rt6key src;
struct rt6key dst;
u8 tclass;
};
struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi *fl,
int flags, pol_lookup_t lookup)
{
struct fib_lookup_arg arg = {
.lookup_ptr = lookup,
};
fib_rules_lookup(net->ipv6.fib6_rules_ops, fl, flags, &arg);
if (arg.rule)
fib_rule_put(arg.rule);
if (arg.result)
return arg.result;
dst_hold(&net->ipv6.ip6_null_entry->u.dst);
return &net->ipv6.ip6_null_entry->u.dst;
}
static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
int flags, struct fib_lookup_arg *arg)
{
struct rt6_info *rt = NULL;
struct fib6_table *table;
struct net *net = rule->fr_net;
pol_lookup_t lookup = arg->lookup_ptr;
switch (rule->action) {
case FR_ACT_TO_TBL:
break;
case FR_ACT_UNREACHABLE:
rt = net->ipv6.ip6_null_entry;
goto discard_pkt;
default:
case FR_ACT_BLACKHOLE:
rt = net->ipv6.ip6_blk_hole_entry;
goto discard_pkt;
case FR_ACT_PROHIBIT:
rt = net->ipv6.ip6_prohibit_entry;
goto discard_pkt;
}
table = fib6_get_table(net, rule->table);
if (table)
rt = lookup(net, table, flp, flags);
if (rt != net->ipv6.ip6_null_entry) {
struct fib6_rule *r = (struct fib6_rule *)rule;
/*
* If we need to find a source address for this traffic,
* we check the result if it meets requirement of the rule.
*/
if ((rule->flags & FIB_RULE_FIND_SADDR) &&
r->src.plen && !(flags & RT6_LOOKUP_F_HAS_SADDR)) {
struct in6_addr saddr;
if (ipv6_dev_get_saddr(net,
ip6_dst_idev(&rt->u.dst)->dev,
&flp->fl6_dst,
rt6_flags2srcprefs(flags),
&saddr))
goto again;
if (!ipv6_prefix_equal(&saddr, &r->src.addr,
r->src.plen))
goto again;
ipv6_addr_copy(&flp->fl6_src, &saddr);
}
goto out;
}
again:
dst_release(&rt->u.dst);
rt = NULL;
goto out;
discard_pkt:
dst_hold(&rt->u.dst);
out:
arg->result = rt;
return rt == NULL ? -EAGAIN : 0;
}
static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
{
struct fib6_rule *r = (struct fib6_rule *) rule;
if (r->dst.plen &&
!ipv6_prefix_equal(&fl->fl6_dst, &r->dst.addr, r->dst.plen))
return 0;
/*
* If FIB_RULE_FIND_SADDR is set and we do not have a
* source address for the traffic, we defer check for
* source address.
*/
if (r->src.plen) {
if (flags & RT6_LOOKUP_F_HAS_SADDR) {
if (!ipv6_prefix_equal(&fl->fl6_src, &r->src.addr,
r->src.plen))
return 0;
} else if (!(r->common.flags & FIB_RULE_FIND_SADDR))
return 0;
}
if (r->tclass && r->tclass != ((ntohl(fl->fl6_flowlabel) >> 20) & 0xff))
return 0;
return 1;
}
static const struct nla_policy fib6_rule_policy[FRA_MAX+1] = {
FRA_GENERIC_POLICY,
};
static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
struct fib_rule_hdr *frh,
struct nlattr **tb)
{
int err = -EINVAL;
struct net *net = sock_net(skb->sk);
struct fib6_rule *rule6 = (struct fib6_rule *) rule;
if (rule->action == FR_ACT_TO_TBL) {
if (rule->table == RT6_TABLE_UNSPEC)
goto errout;
if (fib6_new_table(net, rule->table) == NULL) {
err = -ENOBUFS;
goto errout;
}
}
if (frh->src_len)
nla_memcpy(&rule6->src.addr, tb[FRA_SRC],
sizeof(struct in6_addr));
if (frh->dst_len)
nla_memcpy(&rule6->dst.addr, tb[FRA_DST],
sizeof(struct in6_addr));
rule6->src.plen = frh->src_len;
rule6->dst.plen = frh->dst_len;
rule6->tclass = frh->tos;
err = 0;
errout:
return err;
}
static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
struct nlattr **tb)
{
struct fib6_rule *rule6 = (struct fib6_rule *) rule;
if (frh->src_len && (rule6->src.plen != frh->src_len))
return 0;
if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
return 0;
if (frh->tos && (rule6->tclass != frh->tos))
return 0;
if (frh->src_len &&
nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
return 0;
if (frh->dst_len &&
nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
return 0;
return 1;
}
static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
struct fib_rule_hdr *frh)
{
struct fib6_rule *rule6 = (struct fib6_rule *) rule;
frh->dst_len = rule6->dst.plen;
frh->src_len = rule6->src.plen;
frh->tos = rule6->tclass;
if (rule6->dst.plen)
NLA_PUT(skb, FRA_DST, sizeof(struct in6_addr),
&rule6->dst.addr);
if (rule6->src.plen)
NLA_PUT(skb, FRA_SRC, sizeof(struct in6_addr),
&rule6->src.addr);
return 0;
nla_put_failure:
return -ENOBUFS;
}
static u32 fib6_rule_default_pref(struct fib_rules_ops *ops)
{
return 0x3FFF;
}
static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule)
{
return nla_total_size(16) /* dst */
+ nla_total_size(16); /* src */
}
static const struct fib_rules_ops __net_initdata fib6_rules_ops_template = {
.family = AF_INET6,
.rule_size = sizeof(struct fib6_rule),
.addr_size = sizeof(struct in6_addr),
.action = fib6_rule_action,
.match = fib6_rule_match,
.configure = fib6_rule_configure,
.compare = fib6_rule_compare,
.fill = fib6_rule_fill,
.default_pref = fib6_rule_default_pref,
.nlmsg_payload = fib6_rule_nlmsg_payload,
.nlgroup = RTNLGRP_IPV6_RULE,
.policy = fib6_rule_policy,
.owner = THIS_MODULE,
.fro_net = &init_net,
};
static int __net_init fib6_rules_net_init(struct net *net)
{
struct fib_rules_ops *ops;
int err = -ENOMEM;
ops = fib_rules_register(&fib6_rules_ops_template, net);
if (IS_ERR(ops))
return PTR_ERR(ops);
net->ipv6.fib6_rules_ops = ops;
err = fib_default_rule_add(net->ipv6.fib6_rules_ops, 0,
RT6_TABLE_LOCAL, 0);
if (err)
goto out_fib6_rules_ops;
err = fib_default_rule_add(net->ipv6.fib6_rules_ops,
0x7FFE, RT6_TABLE_MAIN, 0);
if (err)
goto out_fib6_rules_ops;
out:
return err;
out_fib6_rules_ops:
fib_rules_unregister(ops);
goto out;
}
static void __net_exit fib6_rules_net_exit(struct net *net)
{
fib_rules_unregister(net->ipv6.fib6_rules_ops);
}
static struct pernet_operations fib6_rules_net_ops = {
.init = fib6_rules_net_init,
.exit = fib6_rules_net_exit,
};
int __init fib6_rules_init(void)
{
return register_pernet_subsys(&fib6_rules_net_ops);
}
void fib6_rules_cleanup(void)
{
unregister_pernet_subsys(&fib6_rules_net_ops);
}