[PATCH] netfilter: Fix switch statement warnings with recent gcc.

[PATCH] netfilter: Fix switch statement warnings with recent gcc.

[David Miller]

More recent GCC warns about two kinds of switch statement uses:

1) Switching on an enumeration, but not having an explicit case
   statement for all members of the enumeration.  To show the
   compiler this is intentional, we simply add a default case
   with nothing more than a break statement.

2) Switching on a boolean value.  I think this warning is dumb
   but nevertheless you get it wholesale with -Wswitch.

This patch cures all such warnings in netfilter.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/bridge/netfilter/nft_reject_bridge.c b/net/bridge/netfilter/nft_reject_bridge.c
index 54a2fdf..ae8141f 100644
--- a/net/bridge/netfilter/nft_reject_bridge.c
+++ b/net/bridge/netfilter/nft_reject_bridge.c
@@ -371,6 +371,8 @@ static int nft_reject_bridge_dump(struct sk_buff *skb,
 		if (nla_put_u8(skb, NFTA_REJECT_ICMP_CODE, priv->icmp_code))
 			goto nla_put_failure;
 		break;
+	default:
+		break;
 	}
 
 	return 0;
diff --git a/net/ipv4/netfilter/nft_reject_ipv4.c b/net/ipv4/netfilter/nft_reject_ipv4.c
index 16a5d4d..a7621fa 100644
--- a/net/ipv4/netfilter/nft_reject_ipv4.c
+++ b/net/ipv4/netfilter/nft_reject_ipv4.c
@@ -33,6 +33,8 @@ static void nft_reject_ipv4_eval(const struct nft_expr *expr,
 	case NFT_REJECT_TCP_RST:
 		nf_send_reset(pkt->skb, pkt->ops->hooknum);
 		break;
+	default:
+		break;
 	}
 
 	data[NFT_REG_VERDICT].verdict = NF_DROP;
diff --git a/net/ipv6/netfilter/nft_reject_ipv6.c b/net/ipv6/netfilter/nft_reject_ipv6.c
index f732859..71c7be5 100644
--- a/net/ipv6/netfilter/nft_reject_ipv6.c
+++ b/net/ipv6/netfilter/nft_reject_ipv6.c
@@ -34,6 +34,8 @@ static void nft_reject_ipv6_eval(const struct nft_expr *expr,
 	case NFT_REJECT_TCP_RST:
 		nf_send_reset6(net, pkt->skb, pkt->ops->hooknum);
 		break;
+	default:
+		break;
 	}
 
 	data[NFT_REG_VERDICT].verdict = NF_DROP;
diff --git a/net/netfilter/nft_compat.c b/net/netfilter/nft_compat.c
index 589b848..bdefefe 100644
--- a/net/netfilter/nft_compat.c
+++ b/net/netfilter/nft_compat.c
@@ -321,11 +321,11 @@ static void nft_match_eval(const struct nft_expr *expr,
 		return;
 	}
 
-	switch(ret) {
-	case true:
+	switch (ret ? 1 : 0) {
+	case 1:
 		data[NFT_REG_VERDICT].verdict = NFT_CONTINUE;
 		break;
-	case false:
+	case 0:
 		data[NFT_REG_VERDICT].verdict = NFT_BREAK;
 		break;
 	}
diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c
index cc56030..18d520e 100644
--- a/net/netfilter/nft_ct.c
+++ b/net/netfilter/nft_ct.c
@@ -56,6 +56,8 @@ static void nft_ct_get_eval(const struct nft_expr *expr,
 			state = NF_CT_STATE_BIT(ctinfo);
 		dest->data[0] = state;
 		return;
+	default:
+		break;
 	}
 
 	if (ct == NULL)
@@ -117,6 +119,8 @@ static void nft_ct_get_eval(const struct nft_expr *expr,
 		return;
 	}
 #endif
+	default:
+		break;
 	}
 
 	tuple = &ct->tuplehash[priv->dir].tuple;
@@ -141,6 +145,8 @@ static void nft_ct_get_eval(const struct nft_expr *expr,
 	case NFT_CT_PROTO_DST:
 		dest->data[0] = (__force __u16)tuple->dst.u.all;
 		return;
+	default:
+		break;
 	}
 	return;
 err:
@@ -172,6 +178,8 @@ static void nft_ct_set_eval(const struct nft_expr *expr,
 		}
 		break;
 #endif
+	default:
+		break;
 	}
 }
 

Re: [PATCH] netfilter: Fix switch statement warnings with recent gcc.

[Pablo Neira Ayuso]

On Tue, Apr 07, 2015 at 11:05:42PM -0400, David Miller wrote:
> 
> More recent GCC warns about two kinds of switch statement uses:
> 
> 1) Switching on an enumeration, but not having an explicit case
>    statement for all members of the enumeration.  To show the
>    compiler this is intentional, we simply add a default case
>    with nothing more than a break statement.
> 
> 2) Switching on a boolean value.  I think this warning is dumb
>    but nevertheless you get it wholesale with -Wswitch.
> 
> This patch cures all such warnings in netfilter.
> 
> Signed-off-by: David S. Miller <davem@davemloft.net>

Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>

Re: [PATCH] netfilter: Fix switch statement warnings with recent gcc.

[David Miller]

From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Wed, 8 Apr 2015 18:46:14 +0200

> On Tue, Apr 07, 2015 at 11:05:42PM -0400, David Miller wrote:
>> 
>> More recent GCC warns about two kinds of switch statement uses:
>> 
>> 1) Switching on an enumeration, but not having an explicit case
>>    statement for all members of the enumeration.  To show the
>>    compiler this is intentional, we simply add a default case
>>    with nothing more than a break statement.
>> 
>> 2) Switching on a boolean value.  I think this warning is dumb
>>    but nevertheless you get it wholesale with -Wswitch.
>> 
>> This patch cures all such warnings in netfilter.
>> 
>> Signed-off-by: David S. Miller <davem@davemloft.net>
> 
> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>

Ok I tossed this into net-next, thanks for reviewing.