2021-10-11 20:27:18

by Florian Westphal

Subject: [PATCH selinux v3] selinux: remove unneeded ipv6 hook wrappers

Netfilter places the protocol number the hook function is getting called
from in state->pf, so we can use that instead of an extra wrapper.

While at it, remove one-line wrappers too and make
selinux_ip_{out,forward,postroute} useable as hook function.

Signed-off-by: Florian Westphal <[email protected]>
---
v3: also remove the one-line wrappers, just adjust function signature
of the actual functions (Ondrej Mosnacek)

security/selinux/hooks.c | 80 +++++++++-------------------------------
1 file changed, 18 insertions(+), 62 deletions(-)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index e7ebd45ca345..3f6462451921 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -5688,10 +5688,11 @@ static int selinux_tun_dev_open(void *security)

#ifdef CONFIG_NETFILTER

-static unsigned int selinux_ip_forward(struct sk_buff *skb,
- const struct net_device *indev,
- u16 family)
+static unsigned int selinux_ip_forward(void *priv, struct sk_buff *skb,
+ const struct nf_hook_state *state)
{
+ const struct net_device *indev = state->in;
+ u16 family = state->pf;
int err;
char *addrp;
u32 peer_sid;
@@ -5746,25 +5747,10 @@ static unsigned int selinux_ip_forward(struct sk_buff *skb,
return NF_ACCEPT;
}

-static unsigned int selinux_ipv4_forward(void *priv,
- struct sk_buff *skb,
- const struct nf_hook_state *state)
-{
- return selinux_ip_forward(skb, state->in, PF_INET);
-}
-
-#if IS_ENABLED(CONFIG_IPV6)
-static unsigned int selinux_ipv6_forward(void *priv,
- struct sk_buff *skb,
- const struct nf_hook_state *state)
-{
- return selinux_ip_forward(skb, state->in, PF_INET6);
-}
-#endif /* IPV6 */
-
-static unsigned int selinux_ip_output(struct sk_buff *skb,
- u16 family)
+static unsigned int selinux_ip_output(void *priv, struct sk_buff *skb,
+ const struct nf_hook_state *state)
{
+ u16 family = state->pf;
struct sock *sk;
u32 sid;

@@ -5804,21 +5790,6 @@ static unsigned int selinux_ip_output(struct sk_buff *skb,
return NF_ACCEPT;
}

-static unsigned int selinux_ipv4_output(void *priv,
- struct sk_buff *skb,
- const struct nf_hook_state *state)
-{
- return selinux_ip_output(skb, PF_INET);
-}
-
-#if IS_ENABLED(CONFIG_IPV6)
-static unsigned int selinux_ipv6_output(void *priv,
- struct sk_buff *skb,
- const struct nf_hook_state *state)
-{
- return selinux_ip_output(skb, PF_INET6);
-}
-#endif /* IPV6 */

static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
int ifindex,
@@ -5854,10 +5825,12 @@ static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
return NF_ACCEPT;
}

-static unsigned int selinux_ip_postroute(struct sk_buff *skb,
- const struct net_device *outdev,
- u16 family)
+static unsigned int selinux_ip_postroute(void *priv,
+ struct sk_buff *skb,
+ const struct nf_hook_state *state)
{
+ const struct net_device *outdev = state->out;
+ u16 family = state->pf;
u32 secmark_perm;
u32 peer_sid;
int ifindex = outdev->ifindex;
@@ -5993,23 +5966,6 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb,

return NF_ACCEPT;
}
-
-static unsigned int selinux_ipv4_postroute(void *priv,
- struct sk_buff *skb,
- const struct nf_hook_state *state)
-{
- return selinux_ip_postroute(skb, state->out, PF_INET);
-}
-
-#if IS_ENABLED(CONFIG_IPV6)
-static unsigned int selinux_ipv6_postroute(void *priv,
- struct sk_buff *skb,
- const struct nf_hook_state *state)
-{
- return selinux_ip_postroute(skb, state->out, PF_INET6);
-}
-#endif /* IPV6 */
-
#endif /* CONFIG_NETFILTER */

static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
@@ -7470,38 +7426,38 @@ DEFINE_LSM(selinux) = {

static const struct nf_hook_ops selinux_nf_ops[] = {
{
- .hook = selinux_ipv4_postroute,
+ .hook = selinux_ip_postroute,
.pf = NFPROTO_IPV4,
.hooknum = NF_INET_POST_ROUTING,
.priority = NF_IP_PRI_SELINUX_LAST,
},
{
- .hook = selinux_ipv4_forward,
+ .hook = selinux_ip_forward,
.pf = NFPROTO_IPV4,
.hooknum = NF_INET_FORWARD,
.priority = NF_IP_PRI_SELINUX_FIRST,
},
{
- .hook = selinux_ipv4_output,
+ .hook = selinux_ip_output,
.pf = NFPROTO_IPV4,
.hooknum = NF_INET_LOCAL_OUT,
.priority = NF_IP_PRI_SELINUX_FIRST,
},
#if IS_ENABLED(CONFIG_IPV6)
{
- .hook = selinux_ipv6_postroute,
+ .hook = selinux_ip_postroute,
.pf = NFPROTO_IPV6,
.hooknum = NF_INET_POST_ROUTING,
.priority = NF_IP6_PRI_SELINUX_LAST,
},
{
- .hook = selinux_ipv6_forward,
+ .hook = selinux_ip_forward,
.pf = NFPROTO_IPV6,
.hooknum = NF_INET_FORWARD,
.priority = NF_IP6_PRI_SELINUX_FIRST,
},
{
- .hook = selinux_ipv6_output,
+ .hook = selinux_ip_output,
.pf = NFPROTO_IPV6,
.hooknum = NF_INET_LOCAL_OUT,
.priority = NF_IP6_PRI_SELINUX_FIRST,
--
2.32.0

2021-10-11 21:52:46

by Paul Moore

Subject: Re: [PATCH selinux v3] selinux: remove unneeded ipv6 hook wrappers

On Mon, Oct 11, 2021 at 4:22 PM Florian Westphal <[email protected]> wrote:
>
> Netfilter places the protocol number the hook function is getting called
> from in state->pf, so we can use that instead of an extra wrapper.
>
> While at it, remove one-line wrappers too and make
> selinux_ip_{out,forward,postroute} useable as hook function.
>
> Signed-off-by: Florian Westphal <[email protected]>
> ---
> v3: also remove the one-line wrappers, just adjust function signature
> of the actual functions (Ondrej Mosnacek)
>
> security/selinux/hooks.c | 80 +++++++++-------------------------------
> 1 file changed, 18 insertions(+), 62 deletions(-)

Merged into selinux/next, thanks Florian!

--
paul moore
http://www.paul-moore.com