netfilter: move route indirection to struct nf_ipv6_ops

We cannot make a direct call to nf_ip6_route() because that would result
in autoloading the 'ipv6' module because of symbol dependencies.
Therefore, define route indirection in nf_ipv6_ops where this really
belongs to.

For IPv4, we can indeed make a direct function call, which is faster,
given IPv4 is built-in in the networking code by default. Still,
CONFIG_INET=n and CONFIG_NETFILTER=y is possible, so define empty inline
stub for IPv4 in such case.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2017-11-27 22:29:52 +01:00
parent 7db9a51e0f
commit 3f87c08c61
12 changed files with 68 additions and 58 deletions

View file

@ -311,8 +311,6 @@ struct nf_queue_entry;
struct nf_afinfo {
unsigned short family;
int (*route)(struct net *net, struct dst_entry **dst,
struct flowi *fl, bool strict);
int (*reroute)(struct net *net, struct sk_buff *skb,
const struct nf_queue_entry *entry);
int route_key_size;
@ -331,6 +329,8 @@ __sum16 nf_checksum(struct sk_buff *skb, unsigned int hook,
__sum16 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
unsigned int dataoff, unsigned int len,
u_int8_t protocol, unsigned short family);
int nf_route(struct net *net, struct dst_entry **dst, struct flowi *fl,
bool strict, unsigned short family);
int nf_register_afinfo(const struct nf_afinfo *afinfo);
void nf_unregister_afinfo(const struct nf_afinfo *afinfo);

View file

@ -24,6 +24,8 @@ __sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
__sum16 nf_ip_checksum_partial(struct sk_buff *skb, unsigned int hook,
unsigned int dataoff, unsigned int len,
u_int8_t protocol);
int nf_ip_route(struct net *net, struct dst_entry **dst, struct flowi *fl,
bool strict);
#else
static inline __sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
unsigned int dataoff, u_int8_t protocol)
@ -38,6 +40,11 @@ static inline __sum16 nf_ip_checksum_partial(struct sk_buff *skb,
{
return 0;
}
static inline int nf_ip_route(struct net *net, struct dst_entry **dst,
struct flowi *fl, bool strict)
{
return -EOPNOTSUPP;
}
#endif /* CONFIG_INET */
#endif /*__LINUX_IP_NETFILTER_H*/

View file

@ -33,6 +33,8 @@ struct nf_ipv6_ops {
__sum16 (*checksum_partial)(struct sk_buff *skb, unsigned int hook,
unsigned int dataoff, unsigned int len,
u_int8_t protocol);
int (*route)(struct net *net, struct dst_entry **dst, struct flowi *fl,
bool strict);
};
#ifdef CONFIG_NETFILTER

View file

@ -101,15 +101,8 @@ static int nf_br_reroute(struct net *net, struct sk_buff *skb,
return 0;
}
static int nf_br_route(struct net *net, struct dst_entry **dst,
struct flowi *fl, bool strict __always_unused)
{
return 0;
}
static const struct nf_afinfo nf_br_afinfo = {
.family = AF_BRIDGE,
.route = nf_br_route,
.reroute = nf_br_reroute,
.route_key_size = 0,
};

View file

@ -150,8 +150,8 @@ __sum16 nf_ip_checksum_partial(struct sk_buff *skb, unsigned int hook,
}
EXPORT_SYMBOL_GPL(nf_ip_checksum_partial);
static int nf_ip_route(struct net *net, struct dst_entry **dst,
struct flowi *fl, bool strict __always_unused)
int nf_ip_route(struct net *net, struct dst_entry **dst, struct flowi *fl,
bool strict __always_unused)
{
struct rtable *rt = ip_route_output_key(net, &fl->u.ip4);
if (IS_ERR(rt))
@ -159,10 +159,10 @@ static int nf_ip_route(struct net *net, struct dst_entry **dst,
*dst = &rt->dst;
return 0;
}
EXPORT_SYMBOL_GPL(nf_ip_route);
static const struct nf_afinfo nf_ip_afinfo = {
.family = AF_INET,
.route = nf_ip_route,
.reroute = nf_ip_reroute,
.route_key_size = sizeof(struct ip_rt_info),
};

View file

@ -170,11 +170,11 @@ static const struct nf_ipv6_ops ipv6ops = {
.fragment = ip6_fragment,
.checksum = nf_ip6_checksum,
.checksum_partial = nf_ip6_checksum_partial,
.route = nf_ip6_route,
};
static const struct nf_afinfo nf_ip6_afinfo = {
.family = AF_INET6,
.route = nf_ip6_route,
.reroute = nf_ip6_reroute,
.route_key_size = sizeof(struct ip6_rt_info),
};

View file

@ -60,7 +60,6 @@ static u32 __nft_fib6_eval_type(const struct nft_fib *priv,
{
const struct net_device *dev = NULL;
const struct nf_ipv6_ops *v6ops;
const struct nf_afinfo *afinfo;
int route_err, addrtype;
struct rt6_info *rt;
struct flowi6 fl6 = {
@ -69,8 +68,8 @@ static u32 __nft_fib6_eval_type(const struct nft_fib *priv,
};
u32 ret = 0;
afinfo = nf_get_afinfo(NFPROTO_IPV6);
if (!afinfo)
v6ops = nf_get_ipv6_ops();
if (!v6ops)
return RTN_UNREACHABLE;
if (priv->flags & NFTA_FIB_F_IIF)
@ -80,12 +79,11 @@ static u32 __nft_fib6_eval_type(const struct nft_fib *priv,
nft_fib6_flowi_init(&fl6, priv, pkt, dev, iph);
v6ops = nf_get_ipv6_ops();
if (dev && v6ops && v6ops->chk_addr(nft_net(pkt), &fl6.daddr, dev, true))
if (dev && v6ops->chk_addr(nft_net(pkt), &fl6.daddr, dev, true))
ret = RTN_LOCAL;
route_err = afinfo->route(nft_net(pkt), (struct dst_entry **)&rt,
flowi6_to_flowi(&fl6), false);
route_err = v6ops->route(nft_net(pkt), (struct dst_entry **)&rt,
flowi6_to_flowi(&fl6), false);
if (route_err)
goto err;

View file

@ -24,6 +24,7 @@
#include <linux/skbuff.h>
#include <net/route.h>
#include <net/ip6_route.h>
#include <linux/netfilter_ipv6.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_core.h>
@ -721,14 +722,8 @@ static int callforward_do_filter(struct net *net,
const union nf_inet_addr *dst,
u_int8_t family)
{
const struct nf_afinfo *afinfo;
int ret = 0;
/* rcu_read_lock()ed by nf_hook_thresh */
afinfo = nf_get_afinfo(family);
if (!afinfo)
return 0;
switch (family) {
case AF_INET: {
struct flowi4 fl1, fl2;
@ -739,10 +734,10 @@ static int callforward_do_filter(struct net *net,
memset(&fl2, 0, sizeof(fl2));
fl2.daddr = dst->ip;
if (!afinfo->route(net, (struct dst_entry **)&rt1,
flowi4_to_flowi(&fl1), false)) {
if (!afinfo->route(net, (struct dst_entry **)&rt2,
flowi4_to_flowi(&fl2), false)) {
if (!nf_ip_route(net, (struct dst_entry **)&rt1,
flowi4_to_flowi(&fl1), false)) {
if (!nf_ip_route(net, (struct dst_entry **)&rt2,
flowi4_to_flowi(&fl2), false)) {
if (rt_nexthop(rt1, fl1.daddr) ==
rt_nexthop(rt2, fl2.daddr) &&
rt1->dst.dev == rt2->dst.dev)
@ -755,18 +750,23 @@ static int callforward_do_filter(struct net *net,
}
#if IS_ENABLED(CONFIG_NF_CONNTRACK_IPV6)
case AF_INET6: {
struct flowi6 fl1, fl2;
const struct nf_ipv6_ops *v6ops;
struct rt6_info *rt1, *rt2;
struct flowi6 fl1, fl2;
v6ops = nf_get_ipv6_ops();
if (!v6ops)
return 0;
memset(&fl1, 0, sizeof(fl1));
fl1.daddr = src->in6;
memset(&fl2, 0, sizeof(fl2));
fl2.daddr = dst->in6;
if (!afinfo->route(net, (struct dst_entry **)&rt1,
flowi6_to_flowi(&fl1), false)) {
if (!afinfo->route(net, (struct dst_entry **)&rt2,
flowi6_to_flowi(&fl2), false)) {
if (!v6ops->route(net, (struct dst_entry **)&rt1,
flowi6_to_flowi(&fl1), false)) {
if (!v6ops->route(net, (struct dst_entry **)&rt2,
flowi6_to_flowi(&fl2), false)) {
if (ipv6_addr_equal(rt6_nexthop(rt1, &fl1.daddr),
rt6_nexthop(rt2, &fl2.daddr)) &&
rt1->dst.dev == rt2->dst.dev)

View file

@ -27,7 +27,7 @@ static u16 get_tcpmss(const struct nft_pktinfo *pkt, const struct dst_entry *skb
{
u32 minlen = sizeof(struct ipv6hdr), mtu = dst_mtu(skbdst);
const struct sk_buff *skb = pkt->skb;
const struct nf_afinfo *ai;
struct dst_entry *dst = NULL;
struct flowi fl;
memset(&fl, 0, sizeof(fl));
@ -43,15 +43,10 @@ static u16 get_tcpmss(const struct nft_pktinfo *pkt, const struct dst_entry *skb
break;
}
ai = nf_get_afinfo(nft_pf(pkt));
if (ai) {
struct dst_entry *dst = NULL;
ai->route(nft_net(pkt), &dst, &fl, false);
if (dst) {
mtu = min(mtu, dst_mtu(dst));
dst_release(dst);
}
nf_route(nft_net(pkt), &dst, &fl, false, nft_pf(pkt));
if (dst) {
mtu = min(mtu, dst_mtu(dst));
dst_release(dst);
}
if (mtu <= minlen || mtu > 0xffff)

View file

@ -48,3 +48,24 @@ __sum16 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
return csum;
}
EXPORT_SYMBOL_GPL(nf_checksum_partial);
int nf_route(struct net *net, struct dst_entry **dst, struct flowi *fl,
bool strict, unsigned short family)
{
const struct nf_ipv6_ops *v6ops;
int ret = 0;
switch (family) {
case AF_INET:
ret = nf_ip_route(net, dst, fl, strict);
break;
case AF_INET6:
v6ops = rcu_dereference(nf_ipv6_ops);
if (v6ops)
ret = v6ops->route(net, dst, fl, strict);
break;
}
return ret;
}
EXPORT_SYMBOL_GPL(nf_route);

View file

@ -48,7 +48,6 @@ static u_int32_t tcpmss_reverse_mtu(struct net *net,
unsigned int family)
{
struct flowi fl;
const struct nf_afinfo *ai;
struct rtable *rt = NULL;
u_int32_t mtu = ~0U;
@ -62,10 +61,8 @@ static u_int32_t tcpmss_reverse_mtu(struct net *net,
memset(fl6, 0, sizeof(*fl6));
fl6->daddr = ipv6_hdr(skb)->saddr;
}
ai = nf_get_afinfo(family);
if (ai != NULL)
ai->route(net, (struct dst_entry **)&rt, &fl, false);
nf_route(net, (struct dst_entry **)&rt, &fl, false, family);
if (rt != NULL) {
mtu = dst_mtu(&rt->dst);
dst_release(&rt->dst);

View file

@ -36,7 +36,7 @@ MODULE_ALIAS("ip6t_addrtype");
static u32 match_lookup_rt6(struct net *net, const struct net_device *dev,
const struct in6_addr *addr, u16 mask)
{
const struct nf_afinfo *afinfo;
const struct nf_ipv6_ops *v6ops;
struct flowi6 flow;
struct rt6_info *rt;
u32 ret = 0;
@ -47,17 +47,14 @@ static u32 match_lookup_rt6(struct net *net, const struct net_device *dev,
if (dev)
flow.flowi6_oif = dev->ifindex;
afinfo = nf_get_afinfo(NFPROTO_IPV6);
if (afinfo != NULL) {
const struct nf_ipv6_ops *v6ops;
v6ops = nf_get_ipv6_ops();
if (v6ops) {
if (dev && (mask & XT_ADDRTYPE_LOCAL)) {
v6ops = nf_get_ipv6_ops();
if (v6ops && v6ops->chk_addr(net, addr, dev, true))
if (v6ops->chk_addr(net, addr, dev, true))
ret = XT_ADDRTYPE_LOCAL;
}
route_err = afinfo->route(net, (struct dst_entry **)&rt,
flowi6_to_flowi(&flow), false);
route_err = v6ops->route(net, (struct dst_entry **)&rt,
flowi6_to_flowi(&flow), false);
} else {
route_err = 1;
}