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netfilter: nf_reject: Fix build warning when CONFIG_BRIDGE_NETFILTER=n

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If CONFIG_BRIDGE_NETFILTER is not enabled, which is the case for x86_64
defconfig, then building nf_reject_ipv4.c and nf_reject_ipv6.c with W=1
using gcc-14 results in the following warnings, which are treated as
errors:

net/ipv4/netfilter/nf_reject_ipv4.c: In function 'nf_send_reset':
net/ipv4/netfilter/nf_reject_ipv4.c:243:23: error: variable 'niph' set but not used [-Werror=unused-but-set-variable]
  243 |         struct iphdr *niph;
      |                       ^~~~
cc1: all warnings being treated as errors
net/ipv6/netfilter/nf_reject_ipv6.c: In function 'nf_send_reset6':
net/ipv6/netfilter/nf_reject_ipv6.c:286:25: error: variable 'ip6h' set but not used [-Werror=unused-but-set-variable]
  286 |         struct ipv6hdr *ip6h;
      |                         ^~~~
cc1: all warnings being treated as errors

Address this by reducing the scope of these local variables to where
they are used, which is code only compiled when CONFIG_BRIDGE_NETFILTER
enabled.

Compile tested and run through netfilter selftests.

Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Closes: https://lore.kernel.org/netfilter-devel/20240906145513.567781-1-andriy.shevchenko@linux.intel.com/
Signed-off-by: Simon Horman <horms@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Simon Horman 2024-09-16 10:50:34 +01:00 committed by Pablo Neira Ayuso
parent 642c89c475
commit fc56878ca1
2 changed files with 6 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
net/ipv4/netfilter/nf_reject_ipv4.c
View File

@ -239,9 +239,8 @@ static int nf_reject_fill_skb_dst(struct sk_buff *skb_in)
void nf_send_reset(struct net *net, struct sock *sk, struct sk_buff *oldskb,
int hook)
{
struct sk_buff *nskb;
struct iphdr *niph;
const struct tcphdr *oth;
struct sk_buff *nskb;
struct tcphdr _oth;
oth = nf_reject_ip_tcphdr_get(oldskb, &_oth, hook);
@ -266,14 +265,12 @@ void nf_send_reset(struct net *net, struct sock *sk, struct sk_buff *oldskb,
nskb->mark = IP4_REPLY_MARK(net, oldskb->mark);
skb_reserve(nskb, LL_MAX_HEADER);
niph = nf_reject_iphdr_put(nskb, oldskb, IPPROTO_TCP,
ip4_dst_hoplimit(skb_dst(nskb)));
nf_reject_iphdr_put(nskb, oldskb, IPPROTO_TCP,
ip4_dst_hoplimit(skb_dst(nskb)));
nf_reject_ip_tcphdr_put(nskb, oldskb, oth);
if (ip_route_me_harder(net, sk, nskb, RTN_UNSPEC))
goto free_nskb;
niph = ip_hdr(nskb);
/* "Never happens" */
if (nskb->len > dst_mtu(skb_dst(nskb)))
goto free_nskb;
@ -290,6 +287,7 @@ void nf_send_reset(struct net *net, struct sock *sk, struct sk_buff *oldskb,
*/
if (nf_bridge_info_exists(oldskb)) {
struct ethhdr *oeth = eth_hdr(oldskb);
struct iphdr *niph = ip_hdr(nskb);
struct net_device *br_indev;
br_indev = nf_bridge_get_physindev(oldskb, net);

5
net/ipv6/netfilter/nf_reject_ipv6.c
View File

@ -283,7 +283,6 @@ void nf_send_reset6(struct net *net, struct sock *sk, struct sk_buff *oldskb,
const struct tcphdr *otcph;
unsigned int otcplen, hh_len;
const struct ipv6hdr *oip6h = ipv6_hdr(oldskb);
struct ipv6hdr *ip6h;
struct dst_entry *dst = NULL;
struct flowi6 fl6;
@ -339,8 +338,7 @@ void nf_send_reset6(struct net *net, struct sock *sk, struct sk_buff *oldskb,
nskb->mark = fl6.flowi6_mark;
skb_reserve(nskb, hh_len + dst->header_len);
ip6h = nf_reject_ip6hdr_put(nskb, oldskb, IPPROTO_TCP,
ip6_dst_hoplimit(dst));
nf_reject_ip6hdr_put(nskb, oldskb, IPPROTO_TCP, ip6_dst_hoplimit(dst));
nf_reject_ip6_tcphdr_put(nskb, oldskb, otcph, otcplen);
nf_ct_attach(nskb, oldskb);
@ -355,6 +353,7 @@ void nf_send_reset6(struct net *net, struct sock *sk, struct sk_buff *oldskb,
*/
if (nf_bridge_info_exists(oldskb)) {
struct ethhdr *oeth = eth_hdr(oldskb);
struct ipv6hdr *ip6h = ipv6_hdr(nskb);
struct net_device *br_indev;
br_indev = nf_bridge_get_physindev(oldskb, net);