net: evaluate net.ipvX.conf.all.* sysctls

net: evaluate net.ipvX.conf.all.* sysctls

[Vincent Bernat]

Some per-interface sysctls are ignoring the "all" variant. This
patchset fixes some of them when such a sysctl is handled as a
boolean. This includes:

 - net.ipvX.conf.all.disable_policy
 - net.ipvX.conf.all.disable_policy.disable_xfrm
 - net.ipv4.conf.all.proxy_arp_pvlan
 - net.ipvX.conf.all.ignore_routes_with_linkdown

Two sysctls are still ignoring the "all" variant as it wouldn't make
much sense for them:

 - net.ipv4.conf.all.tag
 - net.ipv4.conf.all.medium_id

Ideally, the "all" variant should be removed, but there is no simple
alternative to DEVINET_SYSCTL_* macros that would allow one to not
expose and "all" entry.

[PATCH net-next v2 1/3] net: evaluate net.ipvX.conf.all.ignore_routes_with_linkdown

[Vincent Bernat]

Introduced in 0eeb075fad73, the "ignore_routes_with_linkdown" sysctl
ignores a route whose interface is down. It is provided as a
per-interface sysctl. However, while a "all" variant is exposed, it
was a noop since it was never evaluated. We use the usual "or" logic
for this kind of sysctls.

Tested with:

    ip link add type veth # veth0 + veth1
    ip link add type veth # veth1 + veth2
    ip link set up dev veth0
    ip link set up dev veth1 # link-status paired with veth0
    ip link set up dev veth2
    ip link set up dev veth3 # link-status paired with veth2

    # First available path
    ip -4 addr add 203.0.113.${uts#H}/24 dev veth0
    ip -6 addr add 2001:db8:1::${uts#H}/64 dev veth0

    # Second available path
    ip -4 addr add 192.0.2.${uts#H}/24 dev veth2
    ip -6 addr add 2001:db8:2::${uts#H}/64 dev veth2

    # More specific route through first path
    ip -4 route add 198.51.100.0/25 via 203.0.113.254 # via veth0
    ip -6 route add 2001:db8:3::/56 via 2001:db8:1::ff # via veth0

    # Less specific route through second path
    ip -4 route add 198.51.100.0/24 via 192.0.2.254 # via veth2
    ip -6 route add 2001:db8:3::/48 via 2001:db8:2::ff # via veth2

    # H1: enable on "all"
    # H2: enable on "veth0"
    for v in ipv4 ipv6; do
      case $uts in
        H1)
          sysctl -qw net.${v}.conf.all.ignore_routes_with_linkdown=1
          ;;
        H2)
          sysctl -qw net.${v}.conf.veth0.ignore_routes_with_linkdown=1
          ;;
      esac
    done

    set -xe
    # When veth0 is up, best route is through veth0
    ip -o route get 198.51.100.1 | grep -Fw veth0
    ip -o route get 2001:db8:3::1 | grep -Fw veth0

    # When veth0 is down, best route should be through veth2 on H1/H2,
    # but on veth0 on H2
    ip link set down dev veth1 # down veth0
    ip route show
    [ $uts != H3 ] || ip -o route get 198.51.100.1 | grep -Fw veth0
    [ $uts != H3 ] || ip -o route get 2001:db8:3::1 | grep -Fw veth0
    [ $uts = H3 ] || ip -o route get 198.51.100.1 | grep -Fw veth2
    [ $uts = H3 ] || ip -o route get 2001:db8:3::1 | grep -Fw veth2

Without this patch, the two last lines would fail on H1 (the one using
the "all" sysctl). With the patch, everything succeeds as expected.

Also document the sysctl in `ip-sysctl.rst`.

Fixes: 0eeb075fad73 ("net: ipv4 sysctl option to ignore routes when nexthop link is down")
Signed-off-by: Vincent Bernat <vincent@bernat.ch>
---
 Documentation/networking/ip-sysctl.rst | 3 +++
 include/linux/inetdevice.h             | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index 2aaf40b2d2cd..dd2b12a32b73 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -1554,6 +1554,9 @@ igmpv3_unsolicited_report_interval - INTEGER
 
 	Default: 1000 (1 seconds)
 
+ignore_routes_with_linkdown - BOOLEAN
+        Ignore routes whose link is down when performing a FIB lookup.
+
 promote_secondaries - BOOLEAN
 	When a primary IP address is removed from this interface
 	promote a corresponding secondary IP address instead of
diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index 3515ca64e638..3bbcddd22df8 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -126,7 +126,7 @@ static inline void ipv4_devconf_setall(struct in_device *in_dev)
 	  IN_DEV_ORCONF((in_dev), ACCEPT_REDIRECTS)))
 
 #define IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) \
-	IN_DEV_CONF_GET((in_dev), IGNORE_ROUTES_WITH_LINKDOWN)
+	IN_DEV_ORCONF((in_dev), IGNORE_ROUTES_WITH_LINKDOWN)
 
 #define IN_DEV_ARPFILTER(in_dev)	IN_DEV_ORCONF((in_dev), ARPFILTER)
 #define IN_DEV_ARP_ACCEPT(in_dev)	IN_DEV_ORCONF((in_dev), ARP_ACCEPT)
-- 
2.29.2

[PATCH net-next v2 2/3] net: evaluate net.ipv4.conf.all.proxy_arp_pvlan

[Vincent Bernat]

Introduced in 65324144b50b, the "proxy_arp_vlan" sysctl is a
per-interface sysctl to tune proxy ARP support for private VLANs.
While the "all" variant is exposed, it was a noop and never evaluated.
We use the usual "or" logic for this kind of sysctls.

Fixes: 65324144b50b ("net: RFC3069, private VLAN proxy arp support")
Signed-off-by: Vincent Bernat <vincent@bernat.ch>
---
 include/linux/inetdevice.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index 3bbcddd22df8..53aa0343bf69 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -105,7 +105,7 @@ static inline void ipv4_devconf_setall(struct in_device *in_dev)
 
 #define IN_DEV_LOG_MARTIANS(in_dev)	IN_DEV_ORCONF((in_dev), LOG_MARTIANS)
 #define IN_DEV_PROXY_ARP(in_dev)	IN_DEV_ORCONF((in_dev), PROXY_ARP)
-#define IN_DEV_PROXY_ARP_PVLAN(in_dev)	IN_DEV_CONF_GET(in_dev, PROXY_ARP_PVLAN)
+#define IN_DEV_PROXY_ARP_PVLAN(in_dev)	IN_DEV_ORCONF((in_dev), PROXY_ARP_PVLAN)
 #define IN_DEV_SHARED_MEDIA(in_dev)	IN_DEV_ORCONF((in_dev), SHARED_MEDIA)
 #define IN_DEV_TX_REDIRECTS(in_dev)	IN_DEV_ORCONF((in_dev), SEND_REDIRECTS)
 #define IN_DEV_SEC_REDIRECTS(in_dev)	IN_DEV_ORCONF((in_dev), \
-- 
2.29.2

[PATCH net-next v2 3/3] net: evaluate net.ipvX.conf.all.disable_policy and disable_xfrm

[Vincent Bernat]

The disable_policy and disable_xfrm are a per-interface sysctl to
disable IPsec policy or encryption on an interface. However, while a
"all" variant is exposed, it was a noop since it was never evaluated.
We use the usual "or" logic for this kind of sysctls.

Signed-off-by: Vincent Bernat <vincent@bernat.ch>
---
 net/ipv4/route.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index dc2a399cd9f4..a3b60c41cbad 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1741,7 +1741,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 		flags |= RTCF_LOCAL;
 
 	rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
-			   IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
+			   IN_DEV_ORCONF(in_dev, NOPOLICY), false);
 	if (!rth)
 		return -ENOBUFS;
 
@@ -1857,8 +1857,8 @@ static int __mkroute_input(struct sk_buff *skb,
 	}
 
 	rth = rt_dst_alloc(out_dev->dev, 0, res->type,
-			   IN_DEV_CONF_GET(in_dev, NOPOLICY),
-			   IN_DEV_CONF_GET(out_dev, NOXFRM));
+			   IN_DEV_ORCONF(in_dev, NOPOLICY),
+			   IN_DEV_ORCONF(out_dev, NOXFRM));
 	if (!rth) {
 		err = -ENOBUFS;
 		goto cleanup;
@@ -2227,7 +2227,7 @@ out:	return err;
 
 	rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev,
 			   flags | RTCF_LOCAL, res->type,
-			   IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
+			   IN_DEV_ORCONF(in_dev, NOPOLICY), false);
 	if (!rth)
 		goto e_nobufs;
 
@@ -2450,8 +2450,8 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
 
 add:
 	rth = rt_dst_alloc(dev_out, flags, type,
-			   IN_DEV_CONF_GET(in_dev, NOPOLICY),
-			   IN_DEV_CONF_GET(in_dev, NOXFRM));
+			   IN_DEV_ORCONF(in_dev, NOPOLICY),
+			   IN_DEV_ORCONF(in_dev, NOXFRM));
 	if (!rth)
 		return ERR_PTR(-ENOBUFS);
 
-- 
2.29.2

Re: [PATCH net-next v2 3/3] net: evaluate net.ipvX.conf.all.disable_policy and disable_xfrm

[Jakub Kicinski]

On Sat,  7 Nov 2020 20:35:15 +0100 Vincent Bernat wrote:
> The disable_policy and disable_xfrm are a per-interface sysctl to
> disable IPsec policy or encryption on an interface. However, while a
> "all" variant is exposed, it was a noop since it was never evaluated.
> We use the usual "or" logic for this kind of sysctls.
> 
> Signed-off-by: Vincent Bernat <vincent@bernat.ch>

CC Steffen

> diff --git a/net/ipv4/route.c b/net/ipv4/route.c
> index dc2a399cd9f4..a3b60c41cbad 100644
> --- a/net/ipv4/route.c
> +++ b/net/ipv4/route.c
> @@ -1741,7 +1741,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
>  		flags |= RTCF_LOCAL;
>  
>  	rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
> -			   IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
> +			   IN_DEV_ORCONF(in_dev, NOPOLICY), false);
>  	if (!rth)
>  		return -ENOBUFS;
>  
> @@ -1857,8 +1857,8 @@ static int __mkroute_input(struct sk_buff *skb,
>  	}
>  
>  	rth = rt_dst_alloc(out_dev->dev, 0, res->type,
> -			   IN_DEV_CONF_GET(in_dev, NOPOLICY),
> -			   IN_DEV_CONF_GET(out_dev, NOXFRM));
> +			   IN_DEV_ORCONF(in_dev, NOPOLICY),
> +			   IN_DEV_ORCONF(out_dev, NOXFRM));
>  	if (!rth) {
>  		err = -ENOBUFS;
>  		goto cleanup;
> @@ -2227,7 +2227,7 @@ out:	return err;
>  
>  	rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev,
>  			   flags | RTCF_LOCAL, res->type,
> -			   IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
> +			   IN_DEV_ORCONF(in_dev, NOPOLICY), false);
>  	if (!rth)
>  		goto e_nobufs;
>  
> @@ -2450,8 +2450,8 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
>  
>  add:
>  	rth = rt_dst_alloc(dev_out, flags, type,
> -			   IN_DEV_CONF_GET(in_dev, NOPOLICY),
> -			   IN_DEV_CONF_GET(in_dev, NOXFRM));
> +			   IN_DEV_ORCONF(in_dev, NOPOLICY),
> +			   IN_DEV_ORCONF(in_dev, NOXFRM));
>  	if (!rth)
>  		return ERR_PTR(-ENOBUFS);
>  

Re: [PATCH net-next v2 2/3] net: evaluate net.ipv4.conf.all.proxy_arp_pvlan

[Jakub Kicinski]

On Sat,  7 Nov 2020 20:35:14 +0100 Vincent Bernat wrote:
> Introduced in 65324144b50b, the "proxy_arp_vlan" sysctl is a
> per-interface sysctl to tune proxy ARP support for private VLANs.
> While the "all" variant is exposed, it was a noop and never evaluated.
> We use the usual "or" logic for this kind of sysctls.
> 
> Fixes: 65324144b50b ("net: RFC3069, private VLAN proxy arp support")
> Signed-off-by: Vincent Bernat <vincent@bernat.ch>
> ---
>  include/linux/inetdevice.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 

CC Jesper 

I know this is 10 year old code, but can we get an ack for applying
this to net-next?

> diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
> index 3bbcddd22df8..53aa0343bf69 100644
> --- a/include/linux/inetdevice.h
> +++ b/include/linux/inetdevice.h
> @@ -105,7 +105,7 @@ static inline void ipv4_devconf_setall(struct in_device *in_dev)
>  
>  #define IN_DEV_LOG_MARTIANS(in_dev)	IN_DEV_ORCONF((in_dev), LOG_MARTIANS)
>  #define IN_DEV_PROXY_ARP(in_dev)	IN_DEV_ORCONF((in_dev), PROXY_ARP)
> -#define IN_DEV_PROXY_ARP_PVLAN(in_dev)	IN_DEV_CONF_GET(in_dev, PROXY_ARP_PVLAN)
> +#define IN_DEV_PROXY_ARP_PVLAN(in_dev)	IN_DEV_ORCONF((in_dev), PROXY_ARP_PVLAN)
>  #define IN_DEV_SHARED_MEDIA(in_dev)	IN_DEV_ORCONF((in_dev), SHARED_MEDIA)
>  #define IN_DEV_TX_REDIRECTS(in_dev)	IN_DEV_ORCONF((in_dev), SEND_REDIRECTS)
>  #define IN_DEV_SEC_REDIRECTS(in_dev)	IN_DEV_ORCONF((in_dev), \

Re: net: evaluate net.ipvX.conf.all.* sysctls

[Jakub Kicinski]

On Sat,  7 Nov 2020 20:35:12 +0100 Vincent Bernat wrote:
> Some per-interface sysctls are ignoring the "all" variant. This
> patchset fixes some of them when such a sysctl is handled as a
> boolean. This includes:
> 
>  - net.ipvX.conf.all.disable_policy
>  - net.ipvX.conf.all.disable_policy.disable_xfrm
>  - net.ipv4.conf.all.proxy_arp_pvlan
>  - net.ipvX.conf.all.ignore_routes_with_linkdown
> 
> Two sysctls are still ignoring the "all" variant as it wouldn't make
> much sense for them:
> 
>  - net.ipv4.conf.all.tag
>  - net.ipv4.conf.all.medium_id
> 
> Ideally, the "all" variant should be removed, but there is no simple
> alternative to DEVINET_SYSCTL_* macros that would allow one to not
> expose and "all" entry.

Applied to net-next, thanks.

Let's see if anyone complains..

Re: [PATCH net-next v2 2/3] net: evaluate net.ipv4.conf.all.proxy_arp_pvlan

[Jesper Dangaard Brouer]

On Tue, 10 Nov 2020 15:21:18 -0800
Jakub Kicinski <kuba@kernel.org> wrote:

> On Sat,  7 Nov 2020 20:35:14 +0100 Vincent Bernat wrote:
> > Introduced in 65324144b50b, the "proxy_arp_vlan" sysctl is a
                                               ^ pvlan

The sysctl is called "proxy_arp_pvlan"

> > per-interface sysctl to tune proxy ARP support for private VLANs.
> > While the "all" variant is exposed, it was a noop and never evaluated.
> > We use the usual "or" logic for this kind of sysctls.
> > 
> > Fixes: 65324144b50b ("net: RFC3069, private VLAN proxy arp support")
> > Signed-off-by: Vincent Bernat <vincent@bernat.ch>
> > ---
> >  include/linux/inetdevice.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >   
> 
> CC Jesper 
> 
> I know this is 10 year old code, but can we get an ack for applying
> this to net-next?

ACK, I agree that the "all" variant doesn't make sense for proxy_arp_pvlan.

Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>

> > diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
> > index 3bbcddd22df8..53aa0343bf69 100644
> > --- a/include/linux/inetdevice.h
> > +++ b/include/linux/inetdevice.h
> > @@ -105,7 +105,7 @@ static inline void ipv4_devconf_setall(struct in_device *in_dev)
> >  
> >  #define IN_DEV_LOG_MARTIANS(in_dev)	IN_DEV_ORCONF((in_dev), LOG_MARTIANS)
> >  #define IN_DEV_PROXY_ARP(in_dev)	IN_DEV_ORCONF((in_dev), PROXY_ARP)
> > -#define IN_DEV_PROXY_ARP_PVLAN(in_dev)	IN_DEV_CONF_GET(in_dev, PROXY_ARP_PVLAN)
> > +#define IN_DEV_PROXY_ARP_PVLAN(in_dev)	IN_DEV_ORCONF((in_dev), PROXY_ARP_PVLAN)
> >  #define IN_DEV_SHARED_MEDIA(in_dev)	IN_DEV_ORCONF((in_dev), SHARED_MEDIA)
> >  #define IN_DEV_TX_REDIRECTS(in_dev)	IN_DEV_ORCONF((in_dev), SEND_REDIRECTS)
> >  #define IN_DEV_SEC_REDIRECTS(in_dev)	IN_DEV_ORCONF((in_dev), \  

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer