[PATCH nf-next v2 0/2] netfilter: Make IP_NF_IPTABLES_LEGACY selectable

[PATCH nf-next v2 0/2] netfilter: Make IP_NF_IPTABLES_LEGACY selectable

[Breno Leitao]

These two patches make IP_NF_IPTABLES_LEGACY and IP6_NF_IPTABLES_LEGACY
Kconfigs user selectable, avoiding creating an extra dependency by
enabling some other config that would select IP{6}_NF_IPTABLES_LEGACY.

Changelog:

v2:
 * Added the new configuration in the selftest configs (Jakub)
 * Added this simple cover letter

v1:
 * https://lore.kernel.org/all/20240822175537.3626036-1-leitao@debian.org/


Breno Leitao (2):
  netfilter: Make IP_NF_IPTABLES_LEGACY selectable
  netfilter: Make IP6_NF_IPTABLES_LEGACY selectable

 net/ipv4/netfilter/Kconfig         | 19 +++++++++++--------
 net/ipv6/netfilter/Kconfig         | 22 ++++++++++++----------
 tools/testing/selftests/net/config |  2 ++
 3 files changed, 25 insertions(+), 18 deletions(-)

-- 
2.43.5

[PATCH nf-next v2 1/2] netfilter: Make IP_NF_IPTABLES_LEGACY selectable

[Breno Leitao]

This option makes IP_NF_IPTABLES_LEGACY user selectable, giving
users the option to configure iptables without enabling any other
config.

Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Breno Leitao <leitao@debian.org>
---
 net/ipv4/netfilter/Kconfig         | 19 +++++++++++--------
 tools/testing/selftests/net/config |  1 +
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index 1b991b889506..a06c1903183f 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -12,7 +12,12 @@ config NF_DEFRAG_IPV4
 
 # old sockopt interface and eval loop
 config IP_NF_IPTABLES_LEGACY
-	tristate
+	tristate "Legacy IP tables support"
+	default	n
+	select NETFILTER_XTABLES
+	help
+	  iptables is a general, extensible packet identification legacy framework.
+	  This is not needed if you are using iptables over nftables (iptables-nft).
 
 config NF_SOCKET_IPV4
 	tristate "IPv4 socket lookup support"
@@ -177,7 +182,7 @@ config IP_NF_MATCH_TTL
 config IP_NF_FILTER
 	tristate "Packet filtering"
 	default m if NETFILTER_ADVANCED=n
-	select IP_NF_IPTABLES_LEGACY
+	depends on IP_NF_IPTABLES_LEGACY
 	help
 	  Packet filtering defines a table `filter', which has a series of
 	  rules for simple packet filtering at local input, forwarding and
@@ -217,7 +222,7 @@ config IP_NF_NAT
 	default m if NETFILTER_ADVANCED=n
 	select NF_NAT
 	select NETFILTER_XT_NAT
-	select IP_NF_IPTABLES_LEGACY
+	depends on IP_NF_IPTABLES_LEGACY
 	help
 	  This enables the `nat' table in iptables. This allows masquerading,
 	  port forwarding and other forms of full Network Address Port
@@ -258,7 +263,7 @@ endif # IP_NF_NAT
 config IP_NF_MANGLE
 	tristate "Packet mangling"
 	default m if NETFILTER_ADVANCED=n
-	select IP_NF_IPTABLES_LEGACY
+	depends on IP_NF_IPTABLES_LEGACY
 	help
 	  This option adds a `mangle' table to iptables: see the man page for
 	  iptables(8).  This table is used for various packet alterations
@@ -293,7 +298,7 @@ config IP_NF_TARGET_TTL
 # raw + specific targets
 config IP_NF_RAW
 	tristate  'raw table support (required for NOTRACK/TRACE)'
-	select IP_NF_IPTABLES_LEGACY
+	depends on IP_NF_IPTABLES_LEGACY
 	help
 	  This option adds a `raw' table to iptables. This table is the very
 	  first in the netfilter framework and hooks in at the PREROUTING
@@ -305,9 +310,7 @@ config IP_NF_RAW
 # security table for MAC policy
 config IP_NF_SECURITY
 	tristate "Security table"
-	depends on SECURITY
-	depends on NETFILTER_ADVANCED
-	select IP_NF_IPTABLES_LEGACY
+	depends on SECURITY && NETFILTER_ADVANCED && IP_NF_IPTABLES_LEGACY
 	help
 	  This option adds a `security' table to iptables, for use
 	  with Mandatory Access Control (MAC) policy.
diff --git a/tools/testing/selftests/net/config b/tools/testing/selftests/net/config
index 5b9baf708950..784e2965896a 100644
--- a/tools/testing/selftests/net/config
+++ b/tools/testing/selftests/net/config
@@ -35,6 +35,7 @@ CONFIG_IP_DCCP=m
 CONFIG_NF_NAT=m
 CONFIG_IP6_NF_IPTABLES=m
 CONFIG_IP_NF_IPTABLES=m
+CONFIG_IP_NF_IPTABLES_LEGACY=m
 CONFIG_IP6_NF_NAT=m
 CONFIG_IP6_NF_RAW=m
 CONFIG_IP_NF_NAT=m
-- 
2.43.5

[PATCH nf-next v2 2/2] netfilter: Make IP6_NF_IPTABLES_LEGACY selectable

[Breno Leitao]

This option makes IP6_NF_IPTABLES_LEGACY user selectable, giving
users the option to configure iptables without enabling any other
config.

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 net/ipv6/netfilter/Kconfig         | 22 ++++++++++++----------
 tools/testing/selftests/net/config |  1 +
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig
index f3c8e2d918e1..dad0a50d3ef4 100644
--- a/net/ipv6/netfilter/Kconfig
+++ b/net/ipv6/netfilter/Kconfig
@@ -8,7 +8,13 @@ menu "IPv6: Netfilter Configuration"
 
 # old sockopt interface and eval loop
 config IP6_NF_IPTABLES_LEGACY
-	tristate
+	tristate "Legacy IP6 tables support"
+	depends on INET && IPV6
+	select NETFILTER_XTABLES
+	default n
+	help
+	  ip6tables is a general, extensible packet identification legacy framework.
+	  This is not needed if you are using iptables over nftables (iptables-nft).
 
 config NF_SOCKET_IPV6
 	tristate "IPv6 socket lookup support"
@@ -190,7 +196,7 @@ config IP6_NF_TARGET_HL
 config IP6_NF_FILTER
 	tristate "Packet filtering"
 	default m if NETFILTER_ADVANCED=n
-	select IP6_NF_IPTABLES_LEGACY
+	depends on IP6_NF_IPTABLES_LEGACY
 	tristate
 	help
 	  Packet filtering defines a table `filter', which has a series of
@@ -227,7 +233,7 @@ config IP6_NF_TARGET_SYNPROXY
 config IP6_NF_MANGLE
 	tristate "Packet mangling"
 	default m if NETFILTER_ADVANCED=n
-	select IP6_NF_IPTABLES_LEGACY
+	depends on IP6_NF_IPTABLES_LEGACY
 	help
 	  This option adds a `mangle' table to iptables: see the man page for
 	  iptables(8).  This table is used for various packet alterations
@@ -237,7 +243,7 @@ config IP6_NF_MANGLE
 
 config IP6_NF_RAW
 	tristate  'raw table support (required for TRACE)'
-	select IP6_NF_IPTABLES_LEGACY
+	depends on IP6_NF_IPTABLES_LEGACY
 	help
 	  This option adds a `raw' table to ip6tables. This table is the very
 	  first in the netfilter framework and hooks in at the PREROUTING
@@ -249,9 +255,7 @@ config IP6_NF_RAW
 # security table for MAC policy
 config IP6_NF_SECURITY
 	tristate "Security table"
-	depends on SECURITY
-	depends on NETFILTER_ADVANCED
-	select IP6_NF_IPTABLES_LEGACY
+	depends on SECURITY && NETFILTER_ADVANCED && IP6_NF_IPTABLES_LEGACY
 	help
 	  This option adds a `security' table to iptables, for use
 	  with Mandatory Access Control (MAC) policy.
@@ -260,10 +264,8 @@ config IP6_NF_SECURITY
 
 config IP6_NF_NAT
 	tristate "ip6tables NAT support"
-	depends on NF_CONNTRACK
-	depends on NETFILTER_ADVANCED
+	depends on NF_CONNTRACK && NETFILTER_ADVANCED && IP6_NF_IPTABLES_LEGACY
 	select NF_NAT
-	select IP6_NF_IPTABLES_LEGACY
 	select NETFILTER_XT_NAT
 	help
 	  This enables the `nat' table in ip6tables. This allows masquerading,
diff --git a/tools/testing/selftests/net/config b/tools/testing/selftests/net/config
index 784e2965896a..32e04837084e 100644
--- a/tools/testing/selftests/net/config
+++ b/tools/testing/selftests/net/config
@@ -34,6 +34,7 @@ CONFIG_IPV6_SIT=y
 CONFIG_IP_DCCP=m
 CONFIG_NF_NAT=m
 CONFIG_IP6_NF_IPTABLES=m
+CONFIG_IP6_NF_IPTABLES_LEGACY=m
 CONFIG_IP_NF_IPTABLES=m
 CONFIG_IP_NF_IPTABLES_LEGACY=m
 CONFIG_IP6_NF_NAT=m
-- 
2.43.5

Re: [PATCH nf-next v2 0/2] netfilter: Make IP_NF_IPTABLES_LEGACY selectable

[Jakub Kicinski]

On Fri, 23 Aug 2024 10:48:51 -0700 Breno Leitao wrote:
> These two patches make IP_NF_IPTABLES_LEGACY and IP6_NF_IPTABLES_LEGACY
> Kconfigs user selectable, avoiding creating an extra dependency by
> enabling some other config that would select IP{6}_NF_IPTABLES_LEGACY.

Resulting config in CI still differs quite a bit:

--- config.1	2024-08-23 14:19:10.000000000 -0700
+++ config	2024-08-24 05:18:52.000000000 -0700
@@ -1246,7 +1246,7 @@ CONFIG_NETFILTER_XT_MARK=m
 CONFIG_NETFILTER_XT_TARGET_CONNSECMARK=m
 # CONFIG_NETFILTER_XT_TARGET_CT is not set
 # CONFIG_NETFILTER_XT_TARGET_DSCP is not set
-CONFIG_NETFILTER_XT_TARGET_HL=m
+# CONFIG_NETFILTER_XT_TARGET_HL is not set
 # CONFIG_NETFILTER_XT_TARGET_HMARK is not set
 # CONFIG_NETFILTER_XT_TARGET_IDLETIMER is not set
 # CONFIG_NETFILTER_XT_TARGET_LED is not set
@@ -1333,22 +1333,21 @@ CONFIG_NF_TABLES_IPV4=y
 # CONFIG_NF_DUP_IPV4 is not set
 CONFIG_NF_LOG_ARP=m
 CONFIG_NF_LOG_IPV4=m
-CONFIG_NF_REJECT_IPV4=y
+CONFIG_NF_REJECT_IPV4=m
 CONFIG_IP_NF_IPTABLES=m
 # CONFIG_IP_NF_MATCH_AH is not set
 # CONFIG_IP_NF_MATCH_ECN is not set
 CONFIG_IP_NF_MATCH_RPFILTER=m
 # CONFIG_IP_NF_MATCH_TTL is not set
-CONFIG_IP_NF_FILTER=m
-CONFIG_IP_NF_TARGET_REJECT=m
+# CONFIG_IP_NF_FILTER is not set
+# CONFIG_IP_NF_TARGET_REJECT is not set
 # CONFIG_IP_NF_TARGET_SYNPROXY is not set
 CONFIG_IP_NF_NAT=m
-CONFIG_IP_NF_TARGET_MASQUERADE=m
+# CONFIG_IP_NF_TARGET_MASQUERADE is not set
 # CONFIG_IP_NF_TARGET_NETMAP is not set
 # CONFIG_IP_NF_TARGET_REDIRECT is not set
-CONFIG_IP_NF_MANGLE=m
+# CONFIG_IP_NF_MANGLE is not set
 # CONFIG_IP_NF_TARGET_ECN is not set
-CONFIG_IP_NF_TARGET_TTL=m
 CONFIG_IP_NF_RAW=m
 # CONFIG_IP_NF_ARPFILTER is not set
 # end of IP: Netfilter Configuration
@@ -1363,7 +1362,7 @@ CONFIG_NF_TABLES_IPV6=y
 # CONFIG_NFT_DUP_IPV6 is not set
 # CONFIG_NFT_FIB_IPV6 is not set
 # CONFIG_NF_DUP_IPV6 is not set
-CONFIG_NF_REJECT_IPV6=y
+CONFIG_NF_REJECT_IPV6=m
 CONFIG_NF_LOG_IPV6=m
 CONFIG_IP6_NF_IPTABLES=m
 # CONFIG_IP6_NF_MATCH_AH is not set
@@ -1376,11 +1375,10 @@ CONFIG_IP6_NF_MATCH_IPV6HEADER=m
 CONFIG_IP6_NF_MATCH_RPFILTER=m
 # CONFIG_IP6_NF_MATCH_RT is not set
 # CONFIG_IP6_NF_MATCH_SRH is not set
-# CONFIG_IP6_NF_TARGET_HL is not set
-CONFIG_IP6_NF_FILTER=m
-CONFIG_IP6_NF_TARGET_REJECT=m
+# CONFIG_IP6_NF_FILTER is not set
+# CONFIG_IP6_NF_TARGET_REJECT is not set
 # CONFIG_IP6_NF_TARGET_SYNPROXY is not set
-CONFIG_IP6_NF_MANGLE=m
+# CONFIG_IP6_NF_MANGLE is not set
 CONFIG_IP6_NF_RAW=m
 CONFIG_IP6_NF_NAT=m
 # CONFIG_IP6_NF_TARGET_MASQUERADE is not set
-- 
pw-bot: cr

Re: [PATCH nf-next v2 0/2] netfilter: Make IP_NF_IPTABLES_LEGACY selectable

[Breno Leitao]

On Sat, Aug 24, 2024 at 10:37:56AM -0700, Jakub Kicinski wrote:
> On Fri, 23 Aug 2024 10:48:51 -0700 Breno Leitao wrote:
> > These two patches make IP_NF_IPTABLES_LEGACY and IP6_NF_IPTABLES_LEGACY
> > Kconfigs user selectable, avoiding creating an extra dependency by
> > enabling some other config that would select IP{6}_NF_IPTABLES_LEGACY.
> 
> Resulting config in CI still differs quite a bit:

Sorry about it. I wasn't comparing the whole .config.

I will submit a next version that preserve the .config intact when
running:

 # rm -fr .config ; vng --build  --config tools/testing/selftests/net/config

Thanks,
--breno