[PATCH net] net: bpfilter: fix iptables failure if bpfilter_umh is disabled

[PATCH net] net: bpfilter: fix iptables failure if bpfilter_umh is disabled

[Taehee Yoo]

When iptables command is executed, ip_{set/get}sockopt() try to upload
bpfilter.ko if bpfilter is enabled. if it couldn't find bpfilter.ko,
command is failed.
bpfilter.ko is generated if CONFIG_BPFILTER_UMH is enabled.
ip_{set/get}sockopt() only checks CONFIG_BPFILTER.
So that if CONFIG_BPFILTER is enabled and CONFIG_BPFILTER_UMH is disabled,
iptables command is always failed.

test config:
   CONFIG_BPFILTER=y
   # CONFIG_BPFILTER_UMH is not set

test command:
   %iptables -L
   iptables: No chain/target/match by that name.

Fixes: d2ba09c17a06 ("net: add skeleton of bpfilter kernel module")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
---
 net/ipv4/ip_sockglue.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 26c36cccabdc..fffcc130900e 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -1246,7 +1246,7 @@ int ip_setsockopt(struct sock *sk, int level,
 		return -ENOPROTOOPT;
 
 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
-#ifdef CONFIG_BPFILTER
+#if IS_ENABLED(CONFIG_BPFILTER_UMH)
 	if (optname >= BPFILTER_IPT_SO_SET_REPLACE &&
 	    optname < BPFILTER_IPT_SET_MAX)
 		err = bpfilter_ip_set_sockopt(sk, optname, optval, optlen);
@@ -1559,7 +1559,7 @@ int ip_getsockopt(struct sock *sk, int level,
 	int err;
 
 	err = do_ip_getsockopt(sk, level, optname, optval, optlen, 0);
-#ifdef CONFIG_BPFILTER
+#if IS_ENABLED(CONFIG_BPFILTER_UMH)
 	if (optname >= BPFILTER_IPT_SO_GET_INFO &&
 	    optname < BPFILTER_IPT_GET_MAX)
 		err = bpfilter_ip_get_sockopt(sk, optname, optval, optlen);
@@ -1596,7 +1596,7 @@ int compat_ip_getsockopt(struct sock *sk, int level, int optname,
 	err = do_ip_getsockopt(sk, level, optname, optval, optlen,
 		MSG_CMSG_COMPAT);
 
-#ifdef CONFIG_BPFILTER
+#if IS_ENABLED(CONFIG_BPFILTER_UMH)
 	if (optname >= BPFILTER_IPT_SO_GET_INFO &&
 	    optname < BPFILTER_IPT_GET_MAX)
 		err = bpfilter_ip_get_sockopt(sk, optname, optval, optlen);
-- 
2.17.1

Re: [PATCH net] net: bpfilter: fix iptables failure if bpfilter_umh is disabled

[David Miller]

From: Taehee Yoo <ap420073@gmail.com>
Date: Mon,  5 Nov 2018 22:31:41 +0900

> When iptables command is executed, ip_{set/get}sockopt() try to upload
> bpfilter.ko if bpfilter is enabled. if it couldn't find bpfilter.ko,
> command is failed.
> bpfilter.ko is generated if CONFIG_BPFILTER_UMH is enabled.
> ip_{set/get}sockopt() only checks CONFIG_BPFILTER.
> So that if CONFIG_BPFILTER is enabled and CONFIG_BPFILTER_UMH is disabled,
> iptables command is always failed.
> 
> test config:
>    CONFIG_BPFILTER=y
>    # CONFIG_BPFILTER_UMH is not set
> 
> test command:
>    %iptables -L
>    iptables: No chain/target/match by that name.
> 
> Fixes: d2ba09c17a06 ("net: add skeleton of bpfilter kernel module")
> Signed-off-by: Taehee Yoo <ap420073@gmail.com>

Applied, thanks Taehee-ssi.