[PATCH v2] bridge/netfilter: avoid unused label warning

Arnd Bergmann
2015-10-08T12:30:31Z

With the ARM mini2440_defconfig, the bridge netfilter code gets
built with both CONFIG_NF_DEFRAG_IPV4 and CONFIG_NF_DEFRAG_IPV6
disabled, which leads to a harmless gcc warning:

net/bridge/br_netfilter_hooks.c: In function 'br_nf_dev_queue_xmit':
net/bridge/br_netfilter_hooks.c:792:2: warning: label 'drop' defined but not used [-Wunused-label]

This gets rid of the warning by cleaning up the code to avoid
the respective #ifdefs causing this problem, and replacing them
with if(IS_ENABLED()) checks. I have verified that the resulting
object code is unchanged, and an additional advantage is that
we now get compile coverage of the unused functions in more
configurations.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: dd302b59bde0 ("netfilter: bridge: don't leak skb in error paths")
---
Version 2:

Rebased to git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next

diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c
index 13f03671c88d..18905d4781db 100644
--- a/net/bridge/br_netfilter_hooks.c
+++ b/net/bridge/br_netfilter_hooks.c
@@ -111,7 +111,6 @@ static inline __be16 pppoe_proto(const struct sk_buff *skb)
/* largest possible L2 header, see br_nf_dev_queue_xmit() */
#define NF_BRIDGE_MAX_MAC_HEADER_LENGTH (PPPOE_SES_HLEN + ETH_HLEN)

-#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) || IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
struct brnf_frag_data {
char mac[NF_BRIDGE_MAX_MAC_HEADER_LENGTH];
u8 encap_size;
@@ -121,7 +120,6 @@ struct brnf_frag_data {
};

static DEFINE_PER_CPU(struct brnf_frag_data, brnf_frag_data_storage);
-#endif

static void nf_bridge_info_free(struct sk_buff *skb)
{
@@ -666,7 +664,6 @@ static unsigned int br_nf_forward_arp(void *priv,
return NF_STOLEN;
}

-#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) || IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
static int br_nf_push_frag_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
{
struct brnf_frag_data *data;
@@ -696,9 +693,7 @@ static int br_nf_push_frag_xmit_sk(struct sock *sk, struct sk_buff *skb)
struct net *net = dev_net(skb_dst(skb)->dev);
return br_nf_push_frag_xmit(net, sk, skb);
}
-#endif

-#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4)
static int
br_nf_ip_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
int (*output)(struct sock *, struct sk_buff *))
@@ -716,7 +711,6 @@ br_nf_ip_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,

return ip_do_fragment(sk, skb, output);
}
-#endif

static unsigned int nf_bridge_mtu_reduction(const struct sk_buff *skb)
{
@@ -739,11 +733,11 @@ static int br_nf_dev_queue_xmit(struct net *net, struct sock *sk, struct sk_buff

nf_bridge = nf_bridge_info_get(skb);

-#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4)
/* This is wrong! We should preserve the original fragment
* boundaries by preserving frag_list rather than refragmenting.
*/
- if (skb->protocol == htons(ETH_P_IP)) {
+ if (IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) &&
+ skb->protocol == htons(ETH_P_IP)) {
struct brnf_frag_data *data;

if (br_validate_ipv4(net, skb))
@@ -765,9 +759,8 @@ static int br_nf_dev_queue_xmit(struct net *net, struct sock *sk, struct sk_buff

return br_nf_ip_fragment(net, sk, skb, br_nf_push_frag_xmit_sk);
}
-#endif
-#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
- if (skb->protocol == htons(ETH_P_IPV6)) {
+ if (IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) &&
+ skb->protocol == htons(ETH_P_IPV6)) {
const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
struct brnf_frag_data *data;

@@ -791,7 +784,6 @@ static int br_nf_dev_queue_xmit(struct net *net, struct sock *sk, struct sk_buff
kfree_skb(skb);
return -EMSGSIZE;
}
-#endif
nf_bridge_info_free(skb);
return br_dev_queue_push_xmit(net, sk, skb);