blob: 7c20038330104e9c1dd9f93f38667cff9a0fadc0 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* net/ipv6/fib6_rules.c IPv6 Routing Policy Rules
*
* Copyright (C)2003-2006 Helsinki University of Technology
* Copyright (C)2003-2006 USAGI/WIDE Project
*
* Authors
* Thomas Graf <tgraf@suug.ch>
* Ville Nuorvala <vnuorval@tcs.hut.fi>
*/
#include <linux/netdevice.h>
#include <linux/notifier.h>
#include <linux/export.h>
#include <linux/indirect_call_wrapper.h>
#include <net/fib_rules.h>
#include <net/inet_dscp.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;
dscp_t dscp;
};
static bool fib6_rule_matchall(const struct fib_rule *rule)
{
struct fib6_rule *r = container_of(rule, struct fib6_rule, common);
if (r->dst.plen || r->src.plen || r->dscp)
return false;
return fib_rule_matchall(rule);
}
bool fib6_rule_default(const struct fib_rule *rule)
{
if (!fib6_rule_matchall(rule) || rule->action != FR_ACT_TO_TBL ||
rule->l3mdev)
return false;
if (rule->table != RT6_TABLE_LOCAL && rule->table != RT6_TABLE_MAIN)
return false;
return true;
}
EXPORT_SYMBOL_GPL(fib6_rule_default);
int fib6_rules_dump(struct net *net, struct notifier_block *nb,
struct netlink_ext_ack *extack)
{
return fib_rules_dump(net, nb, AF_INET6, extack);
}
unsigned int fib6_rules_seq_read(struct net *net)
{
return fib_rules_seq_read(net, AF_INET6);
}
/* called with rcu lock held; no reference taken on fib6_info */
int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
struct fib6_result *res, int flags)
{
int err;
if (net->ipv6.fib6_has_custom_rules) {
struct fib_lookup_arg arg = {
.lookup_ptr = fib6_table_lookup,
.lookup_data = &oif,
.result = res,
.flags = FIB_LOOKUP_NOREF,
};
l3mdev_update_flow(net, flowi6_to_flowi(fl6));
err = fib_rules_lookup(net->ipv6.fib6_rules_ops,
flowi6_to_flowi(fl6), flags, &arg);
} else {
err = fib6_table_lookup(net, net->ipv6.fib6_local_tbl, oif,
fl6, res, flags);
if (err || res->f6i == net->ipv6.fib6_null_entry)
err = fib6_table_lookup(net, net->ipv6.fib6_main_tbl,
oif, fl6, res, flags);
}
return err;
}
struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
const struct sk_buff *skb,
int flags, pol_lookup_t lookup)
{
if (net->ipv6.fib6_has_custom_rules) {
struct fib6_result res = {};
struct fib_lookup_arg arg = {
.lookup_ptr = lookup,
.lookup_data = skb,
.result = &res,
.flags = FIB_LOOKUP_NOREF,
};
/* update flow if oif or iif point to device enslaved to l3mdev */
l3mdev_update_flow(net, flowi6_to_flowi(fl6));
fib_rules_lookup(net->ipv6.fib6_rules_ops,
flowi6_to_flowi(fl6), flags, &arg);
if (res.rt6)
return &res.rt6->dst;
} else {
struct rt6_info *rt;
rt = pol_lookup_func(lookup,
net, net->ipv6.fib6_local_tbl, fl6, skb, flags);
if (rt != net->ipv6.ip6_null_entry && rt->dst.error != -EAGAIN)
return &rt->dst;
ip6_rt_put_flags(rt, flags);
rt = pol_lookup_func(lookup,
net, net->ipv6.fib6_main_tbl, fl6, skb, flags);
if (rt->dst.error != -EAGAIN)
return &rt->dst;
ip6_rt_put_flags(rt, flags);
}
if (!(flags & RT6_LOOKUP_F_DST_NOREF))
dst_hold(&net->ipv6.ip6_null_entry->dst);
return &net->ipv6.ip6_null_entry->dst;
}
static int fib6_rule_saddr(struct net *net, struct fib_rule *rule, int flags,
struct flowi6 *flp6, const struct net_device *dev)
{
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, dev, &flp6->daddr,
rt6_flags2srcprefs(flags), &saddr))
return -EAGAIN;
if (!ipv6_prefix_equal(&saddr, &r->src.addr, r->src.plen))
return -EAGAIN;
flp6->saddr = saddr;
}
return 0;
}
static int fib6_rule_action_alt(struct fib_rule *rule, struct flowi *flp,
int flags, struct fib_lookup_arg *arg)
{
struct fib6_result *res = arg->result;
struct flowi6 *flp6 = &flp->u.ip6;
struct net *net = rule->fr_net;
struct fib6_table *table;
int err, *oif;
u32 tb_id;
switch (rule->action) {
case FR_ACT_TO_TBL:
break;
case FR_ACT_UNREACHABLE:
return -ENETUNREACH;
case FR_ACT_PROHIBIT:
return -EACCES;
case FR_ACT_BLACKHOLE:
default:
return -EINVAL;
}
tb_id = fib_rule_get_table(rule, arg);
table = fib6_get_table(net, tb_id);
if (!table)
return -EAGAIN;
oif = (int *)arg->lookup_data;
err = fib6_table_lookup(net, table, *oif, flp6, res, flags);
if (!err && res->f6i != net->ipv6.fib6_null_entry)
err = fib6_rule_saddr(net, rule, flags, flp6,
res->nh->fib_nh_dev);
else
err = -EAGAIN;
return err;
}
static int __fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
int flags, struct fib_lookup_arg *arg)
{
struct fib6_result *res = arg->result;
struct flowi6 *flp6 = &flp->u.ip6;
struct rt6_info *rt = NULL;
struct fib6_table *table;
struct net *net = rule->fr_net;
pol_lookup_t lookup = arg->lookup_ptr;
int err = 0;
u32 tb_id;
switch (rule->action) {
case FR_ACT_TO_TBL:
break;
case FR_ACT_UNREACHABLE:
err = -ENETUNREACH;
rt = net->ipv6.ip6_null_entry;
goto discard_pkt;
default:
case FR_ACT_BLACKHOLE:
err = -EINVAL;
rt = net->ipv6.ip6_blk_hole_entry;
goto discard_pkt;
case FR_ACT_PROHIBIT:
err = -EACCES;
rt = net->ipv6.ip6_prohibit_entry;
goto discard_pkt;
}
tb_id = fib_rule_get_table(rule, arg);
table = fib6_get_table(net, tb_id);
if (!table) {
err = -EAGAIN;
goto out;
}
rt = pol_lookup_func(lookup,
net, table, flp6, arg->lookup_data, flags);
if (rt != net->ipv6.ip6_null_entry) {
err = fib6_rule_saddr(net, rule, flags, flp6,
ip6_dst_idev(&rt->dst)->dev);
if (err == -EAGAIN)
goto again;
err = rt->dst.error;
if (err != -EAGAIN)
goto out;
}
again:
ip6_rt_put_flags(rt, flags);
err = -EAGAIN;
rt = NULL;
goto out;
discard_pkt:
if (!(flags & RT6_LOOKUP_F_DST_NOREF))
dst_hold(&rt->dst);
out:
res->rt6 = rt;
return err;
}
INDIRECT_CALLABLE_SCOPE int fib6_rule_action(struct fib_rule *rule,
struct flowi *flp, int flags,
struct fib_lookup_arg *arg)
{
if (arg->lookup_ptr == fib6_table_lookup)
return fib6_rule_action_alt(rule, flp, flags, arg);
return __fib6_rule_action(rule, flp, flags, arg);
}
INDIRECT_CALLABLE_SCOPE bool fib6_rule_suppress(struct fib_rule *rule,
int flags,
struct fib_lookup_arg *arg)
{
struct fib6_result *res = arg->result;
struct rt6_info *rt = res->rt6;
struct net_device *dev = NULL;
if (!rt)
return false;
if (rt->rt6i_idev)
dev = rt->rt6i_idev->dev;
/* do not accept result if the route does
* not meet the required prefix length
*/
if (rt->rt6i_dst.plen <= rule->suppress_prefixlen)
goto suppress_route;
/* do not accept result if the route uses a device
* belonging to a forbidden interface group
*/
if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup)
goto suppress_route;
return false;
suppress_route:
ip6_rt_put_flags(rt, flags);
return true;
}
INDIRECT_CALLABLE_SCOPE int fib6_rule_match(struct fib_rule *rule,
struct flowi *fl, int flags)
{
struct fib6_rule *r = (struct fib6_rule *) rule;
struct flowi6 *fl6 = &fl->u.ip6;
if (r->dst.plen &&
!ipv6_prefix_equal(&fl6->daddr, &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(&fl6->saddr, &r->src.addr,
r->src.plen))
return 0;
} else if (!(r->common.flags & FIB_RULE_FIND_SADDR))
return 0;
}
if (r->dscp && r->dscp != ip6_dscp(fl6->flowlabel))
return 0;
if (rule->ip_proto && (rule->ip_proto != fl6->flowi6_proto))
return 0;
if (fib_rule_port_range_set(&rule->sport_range) &&
!fib_rule_port_inrange(&rule->sport_range, fl6->fl6_sport))
return 0;
if (fib_rule_port_range_set(&rule->dport_range) &&
!fib_rule_port_inrange(&rule->dport_range, fl6->fl6_dport))
return 0;
return 1;
}
static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
struct fib_rule_hdr *frh,
struct nlattr **tb,
struct netlink_ext_ack *extack)
{
int err = -EINVAL;
struct net *net = sock_net(skb->sk);
struct fib6_rule *rule6 = (struct fib6_rule *) rule;
if (!inet_validate_dscp(frh->tos)) {
NL_SET_ERR_MSG(extack,
"Invalid dsfield (tos): ECN bits must be 0");
goto errout;
}
rule6->dscp = inet_dsfield_to_dscp(frh->tos);
if (rule->action == FR_ACT_TO_TBL && !rule->l3mdev) {
if (rule->table == RT6_TABLE_UNSPEC) {
NL_SET_ERR_MSG(extack, "Invalid table");
goto errout;
}
if (fib6_new_table(net, rule->table) == NULL) {
err = -ENOBUFS;
goto errout;
}
}
if (frh->src_len)
rule6->src.addr = nla_get_in6_addr(tb[FRA_SRC]);
if (frh->dst_len)
rule6->dst.addr = nla_get_in6_addr(tb[FRA_DST]);
rule6->src.plen = frh->src_len;
rule6->dst.plen = frh->dst_len;
if (fib_rule_requires_fldissect(rule))
net->ipv6.fib6_rules_require_fldissect++;
net->ipv6.fib6_has_custom_rules = true;
err = 0;
errout:
return err;
}
static int fib6_rule_delete(struct fib_rule *rule)
{
struct net *net = rule->fr_net;
if (net->ipv6.fib6_rules_require_fldissect &&
fib_rule_requires_fldissect(rule))
net->ipv6.fib6_rules_require_fldissect--;
return 0;
}
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 && inet_dscp_to_dsfield(rule6->dscp) != 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 = inet_dscp_to_dsfield(rule6->dscp);
if ((rule6->dst.plen &&
nla_put_in6_addr(skb, FRA_DST, &rule6->dst.addr)) ||
(rule6->src.plen &&
nla_put_in6_addr(skb, FRA_SRC, &rule6->src.addr)))
goto nla_put_failure;
return 0;
nla_put_failure:
return -ENOBUFS;
}
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_initconst 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,
.suppress = fib6_rule_suppress,
.configure = fib6_rule_configure,
.delete = fib6_rule_delete,
.compare = fib6_rule_compare,
.fill = fib6_rule_fill,
.nlmsg_payload = fib6_rule_nlmsg_payload,
.nlgroup = RTNLGRP_IPV6_RULE,
.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;
ops = fib_rules_register(&fib6_rules_ops_template, net);
if (IS_ERR(ops))
return PTR_ERR(ops);
err = fib_default_rule_add(ops, 0, RT6_TABLE_LOCAL, 0);
if (err)
goto out_fib6_rules_ops;
err = fib_default_rule_add(ops, 0x7FFE, RT6_TABLE_MAIN, 0);
if (err)
goto out_fib6_rules_ops;
net->ipv6.fib6_rules_ops = ops;
net->ipv6.fib6_rules_require_fldissect = 0;
out:
return err;
out_fib6_rules_ops:
fib_rules_unregister(ops);
goto out;
}
static void __net_exit fib6_rules_net_exit_batch(struct list_head *net_list)
{
struct net *net;
rtnl_lock();
list_for_each_entry(net, net_list, exit_list) {
fib_rules_unregister(net->ipv6.fib6_rules_ops);
cond_resched();
}
rtnl_unlock();
}
static struct pernet_operations fib6_rules_net_ops = {
.init = fib6_rules_net_init,
.exit_batch = fib6_rules_net_exit_batch,
};
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);
}