clang points out that building without IPv6 would lead to returning
an uninitialized variable if a packet with family!=AF_INET is
passed into bareudp_udp_encap_recv():
drivers/net/bareudp.c:139:6: error: variable 'err' is used uninitialized
whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
if (family == AF_INET)
^~~~~~~~~~~~~~~~~
drivers/net/bareudp.c:146:15: note: uninitialized use occurs here
if (unlikely(err)) {
^~~
include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^
drivers/net/bareudp.c:139:2: note: remove the 'if' if its condition is always
true
if (family == AF_INET)
^~~~~~~~~~~~~~~~~~~~~~
This cannot happen in practice, so change the condition in a way that
gcc sees the IPv4 case as unconditionally true here.
For consistency, change all the similar constructs in this file the
same way, using "if(IS_ENABLED())" instead of #if IS_ENABLED()".
Fixes: 571912c69f0e ("net: UDP tunnel encapsulation module for tunnelling
different protocols like MPLS, IP, NSH etc.")
Signed-off-by: Arnd Bergmann <a...@arndb.de>
---
drivers/net/bareudp.c | 18 ++++--------------
include/net/udp_tunnel.h | 2 --
2 files changed, 4 insertions(+), 16 deletions(-)
diff --git a/drivers/net/bareudp.c b/drivers/net/bareudp.c
index cc0703c3d57f..efd1a1d1f35e 100644
--- a/drivers/net/bareudp.c
+++ b/drivers/net/bareudp.c
@@ -136,25 +136,21 @@ static int bareudp_udp_encap_recv(struct sock *sk, struct
sk_buff *skb)
oiph = skb_network_header(skb);
skb_reset_network_header(skb);
- if (family == AF_INET)
+ if (!IS_ENABLED(CONFIG_IPV6) || family == AF_INET)
err = IP_ECN_decapsulate(oiph, skb);
-#if IS_ENABLED(CONFIG_IPV6)
else
err = IP6_ECN_decapsulate(oiph, skb);
-#endif
if (unlikely(err)) {
if (log_ecn_error) {
- if (family == AF_INET)
+ if (!IS_ENABLED(CONFIG_IPV6) || family == AF_INET)
net_info_ratelimited("non-ECT from %pI4 "
"with TOS=%#x\n",
&((struct iphdr
*)oiph)->saddr,
((struct iphdr
*)oiph)->tos);
-#if IS_ENABLED(CONFIG_IPV6)
else
net_info_ratelimited("non-ECT from %pI6\n",
&((struct ipv6hdr
*)oiph)->saddr);
-#endif
}
if (err > 1) {
++bareudp->dev->stats.rx_frame_errors;
@@ -350,7 +346,6 @@ static int bareudp_xmit_skb(struct sk_buff *skb, struct
net_device *dev,
return err;
}
-#if IS_ENABLED(CONFIG_IPV6)
static int bareudp6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
struct bareudp_dev *bareudp,
const struct ip_tunnel_info *info)
@@ -411,7 +406,6 @@ static int bareudp6_xmit_skb(struct sk_buff *skb, struct
net_device *dev,
dst_release(dst);
return err;
}
-#endif
static netdev_tx_t bareudp_xmit(struct sk_buff *skb, struct net_device *dev)
{
@@ -435,11 +429,9 @@ static netdev_tx_t bareudp_xmit(struct sk_buff *skb,
struct net_device *dev)
}
rcu_read_lock();
-#if IS_ENABLED(CONFIG_IPV6)
- if (info->mode & IP_TUNNEL_INFO_IPV6)
+ if (IS_ENABLED(CONFIG_IPV6) && info->mode & IP_TUNNEL_INFO_IPV6)
err = bareudp6_xmit_skb(skb, dev, bareudp, info);
else
-#endif
err = bareudp_xmit_skb(skb, dev, bareudp, info);
rcu_read_unlock();
@@ -467,7 +459,7 @@ static int bareudp_fill_metadata_dst(struct net_device *dev,
use_cache = ip_tunnel_dst_cache_usable(skb, info);
- if (ip_tunnel_info_af(info) == AF_INET) {
+ if (!IS_ENABLED(CONFIG_IPV6) || ip_tunnel_info_af(info) == AF_INET) {
struct rtable *rt;
__be32 saddr;
@@ -478,7 +470,6 @@ static int bareudp_fill_metadata_dst(struct net_device *dev,
ip_rt_put(rt);
info->key.u.ipv4.src = saddr;
-#if IS_ENABLED(CONFIG_IPV6)
} else if (ip_tunnel_info_af(info) == AF_INET6) {
struct dst_entry *dst;
struct in6_addr saddr;
@@ -492,7 +483,6 @@ static int bareudp_fill_metadata_dst(struct net_device *dev,
dst_release(dst);
info->key.u.ipv6.src = saddr;
-#endif
} else {
return -EINVAL;
}
diff --git a/include/net/udp_tunnel.h b/include/net/udp_tunnel.h
index 4b1f95e08307..e7312ceb2794 100644
--- a/include/net/udp_tunnel.h
+++ b/include/net/udp_tunnel.h
@@ -143,14 +143,12 @@ void udp_tunnel_xmit_skb(struct rtable *rt, struct sock
*sk, struct sk_buff *skb
__be16 df, __be16 src_port, __be16 dst_port,
bool xnet, bool nocheck);
-#if IS_ENABLED(CONFIG_IPV6)
int udp_tunnel6_xmit_skb(struct dst_entry *dst, struct sock *sk,
struct sk_buff *skb,
struct net_device *dev, struct in6_addr *saddr,
struct in6_addr *daddr,
__u8 prio, __u8 ttl, __be32 label,
__be16 src_port, __be16 dst_port, bool nocheck);
-#endif
void udp_tunnel_sock_release(struct socket *sock);
--
2.26.0
