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netfilter: ipv6: avoid indirect calls for IPV6=y case
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indirect calls are only needed if ipv6 is a module.
Add helpers to abstract the v6ops indirections and use them instead.

fragment, reroute and route_input are kept as indirect calls.
The first two are not not used in hot path and route_input is only
used by bridge netfilter.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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@ummakynes
Florian Westphal authored and ummakynes committed Feb 4, 2019
1 parent 9605872 commit ac02bcf
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Showing 5 changed files with 68 additions and 42 deletions.
64 changes: 51 additions & 13 deletions include/linux/netfilter_ipv6.h
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Original file line number Diff line number Diff line change
Expand Up @@ -25,36 +25,74 @@ struct nf_queue_entry;
* if IPv6 is a module.
*/
struct nf_ipv6_ops {
#if IS_MODULE(CONFIG_IPV6)
int (*chk_addr)(struct net *net, const struct in6_addr *addr,
const struct net_device *dev, int strict);
void (*route_input)(struct sk_buff *skb);
int (*fragment)(struct net *net, struct sock *sk, struct sk_buff *skb,
int (*output)(struct net *, struct sock *, struct sk_buff *));
int (*route)(struct net *net, struct dst_entry **dst, struct flowi *fl,
bool strict);
int (*reroute)(struct sk_buff *skb, const struct nf_queue_entry *entry);
#if IS_MODULE(CONFIG_IPV6)
int (*route_me_harder)(struct net *net, struct sk_buff *skb);
int (*dev_get_saddr)(struct net *net, const struct net_device *dev,
const struct in6_addr *daddr, unsigned int srcprefs,
struct in6_addr *saddr);
int (*route)(struct net *net, struct dst_entry **dst, struct flowi *fl,
bool strict);
#endif
void (*route_input)(struct sk_buff *skb);
int (*fragment)(struct net *net, struct sock *sk, struct sk_buff *skb,
int (*output)(struct net *, struct sock *, struct sk_buff *));
int (*reroute)(struct sk_buff *skb, const struct nf_queue_entry *entry);
};

#ifdef CONFIG_NETFILTER
int ip6_route_me_harder(struct net *net, struct sk_buff *skb);
__sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
unsigned int dataoff, u_int8_t protocol);

int ipv6_netfilter_init(void);
void ipv6_netfilter_fini(void);
#include <net/addrconf.h>

extern const struct nf_ipv6_ops __rcu *nf_ipv6_ops;
static inline const struct nf_ipv6_ops *nf_get_ipv6_ops(void)
{
return rcu_dereference(nf_ipv6_ops);
}

static inline int nf_ipv6_chk_addr(struct net *net, const struct in6_addr *addr,
const struct net_device *dev, int strict)
{
#if IS_MODULE(CONFIG_IPV6)
const struct nf_ipv6_ops *v6_ops = nf_get_ipv6_ops();

if (!v6_ops)
return 1;

return v6_ops->chk_addr(net, addr, dev, strict);
#else
return ipv6_chk_addr(net, addr, dev, strict);
#endif
}

int __nf_ip6_route(struct net *net, struct dst_entry **dst,
struct flowi *fl, bool strict);

static inline int nf_ip6_route(struct net *net, struct dst_entry **dst,
struct flowi *fl, bool strict)
{
#if IS_MODULE(CONFIG_IPV6)
const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();

if (v6ops)
return v6ops->route(net, dst, fl, strict);

return -EHOSTUNREACH;
#endif
#if IS_BUILTIN(CONFIG_IPV6)
return __nf_ip6_route(net, dst, fl, strict);
#else
return -EHOSTUNREACH;
#endif
}

int ip6_route_me_harder(struct net *net, struct sk_buff *skb);
__sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
unsigned int dataoff, u_int8_t protocol);

int ipv6_netfilter_init(void);
void ipv6_netfilter_fini(void);

#else /* CONFIG_NETFILTER */
static inline int ipv6_netfilter_init(void) { return 0; }
static inline void ipv6_netfilter_fini(void) { return; }
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15 changes: 8 additions & 7 deletions net/ipv6/netfilter.c
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Original file line number Diff line number Diff line change
Expand Up @@ -84,8 +84,8 @@ static int nf_ip6_reroute(struct sk_buff *skb,
return 0;
}

static int nf_ip6_route(struct net *net, struct dst_entry **dst,
struct flowi *fl, bool strict)
int __nf_ip6_route(struct net *net, struct dst_entry **dst,
struct flowi *fl, bool strict)
{
static const struct ipv6_pinfo fake_pinfo;
static const struct inet_sock fake_sk = {
Expand All @@ -105,17 +105,18 @@ static int nf_ip6_route(struct net *net, struct dst_entry **dst,
*dst = result;
return err;
}
EXPORT_SYMBOL_GPL(__nf_ip6_route);

static const struct nf_ipv6_ops ipv6ops = {
.chk_addr = ipv6_chk_addr,
.route_input = ip6_route_input,
.fragment = ip6_fragment,
.route = nf_ip6_route,
.reroute = nf_ip6_reroute,
#if IS_MODULE(CONFIG_IPV6)
.chk_addr = ipv6_chk_addr,
.route_me_harder = ip6_route_me_harder,
.dev_get_saddr = ipv6_dev_get_saddr,
.route = __nf_ip6_route,
#endif
.route_input = ip6_route_input,
.fragment = ip6_fragment,
.reroute = nf_ip6_reroute,
};

int __init ipv6_netfilter_init(void)
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9 changes: 2 additions & 7 deletions net/ipv6/netfilter/nft_fib_ipv6.c
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Original file line number Diff line number Diff line change
Expand Up @@ -59,7 +59,6 @@ static u32 __nft_fib6_eval_type(const struct nft_fib *priv,
struct ipv6hdr *iph)
{
const struct net_device *dev = NULL;
const struct nf_ipv6_ops *v6ops;
int route_err, addrtype;
struct rt6_info *rt;
struct flowi6 fl6 = {
Expand All @@ -68,21 +67,17 @@ static u32 __nft_fib6_eval_type(const struct nft_fib *priv,
};
u32 ret = 0;

v6ops = nf_get_ipv6_ops();
if (!v6ops)
return RTN_UNREACHABLE;

if (priv->flags & NFTA_FIB_F_IIF)
dev = nft_in(pkt);
else if (priv->flags & NFTA_FIB_F_OIF)
dev = nft_out(pkt);

nft_fib6_flowi_init(&fl6, priv, pkt, dev, iph);

if (dev && v6ops->chk_addr(nft_net(pkt), &fl6.daddr, dev, true))
if (dev && nf_ipv6_chk_addr(nft_net(pkt), &fl6.daddr, dev, true))
ret = RTN_LOCAL;

route_err = v6ops->route(nft_net(pkt), (struct dst_entry **)&rt,
route_err = nf_ip6_route(nft_net(pkt), (struct dst_entry **)&rt,
flowi6_to_flowi(&fl6), false);
if (route_err)
goto err;
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6 changes: 2 additions & 4 deletions net/netfilter/utils.c
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Original file line number Diff line number Diff line change
Expand Up @@ -162,17 +162,15 @@ 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;
const struct nf_ipv6_ops *v6ops __maybe_unused;
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);
ret = nf_ip6_route(net, dst, fl, strict);
break;
}

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16 changes: 5 additions & 11 deletions net/netfilter/xt_addrtype.c
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Original file line number Diff line number Diff line change
Expand Up @@ -36,7 +36,6 @@ 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_ipv6_ops *v6ops;
struct flowi6 flow;
struct rt6_info *rt;
u32 ret = 0;
Expand All @@ -47,18 +46,13 @@ static u32 match_lookup_rt6(struct net *net, const struct net_device *dev,
if (dev)
flow.flowi6_oif = dev->ifindex;

v6ops = nf_get_ipv6_ops();
if (v6ops) {
if (dev && (mask & XT_ADDRTYPE_LOCAL)) {
if (v6ops->chk_addr(net, addr, dev, true))
ret = XT_ADDRTYPE_LOCAL;
}
route_err = v6ops->route(net, (struct dst_entry **)&rt,
flowi6_to_flowi(&flow), false);
} else {
route_err = 1;
if (dev && (mask & XT_ADDRTYPE_LOCAL)) {
if (nf_ipv6_chk_addr(net, addr, dev, true))
ret = XT_ADDRTYPE_LOCAL;
}

route_err = nf_ip6_route(net, (struct dst_entry **)&rt,
flowi6_to_flowi(&flow), false);
if (route_err)
return XT_ADDRTYPE_UNREACHABLE;

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