[PATCH] conf: Fix erroneous check of ip6->gw

[PATCH] conf: Fix erroneous check of ip6->gw

[David Gibson]

a7359f094898 ("conf: Don't exit if sourced default route has no gateway")
was supposed to allow passt/pasta to run even if given a template interface
which has no default gateway.  However a mistake in the patch means it
still requires the gateway, but doesn't require a global address for the
guest which we really do need.

This is one part (but not the only part) of the problem seen in
https://bugs.passt.top/show_bug.cgi?id=50.

Fixes: a7359f094898

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 conf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/conf.c b/conf.c
index d8414fe7..ffff235b 100644
--- a/conf.c
+++ b/conf.c
@@ -708,7 +708,7 @@ static unsigned int conf_ip6(unsigned int ifi,
 	if (MAC_IS_ZERO(mac))
 		nl_link(0, ifi, mac, 0, 0);
 
-	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->gw) ||
+	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->addr) ||
 	    IN6_IS_ADDR_UNSPECIFIED(&ip6->addr_ll) ||
 	    MAC_IS_ZERO(mac))
 		return 0;
-- 
@@ -708,7 +708,7 @@ static unsigned int conf_ip6(unsigned int ifi,
 	if (MAC_IS_ZERO(mac))
 		nl_link(0, ifi, mac, 0, 0);
 
-	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->gw) ||
+	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->addr) ||
 	    IN6_IS_ADDR_UNSPECIFIED(&ip6->addr_ll) ||
 	    MAC_IS_ZERO(mac))
 		return 0;
-- 
2.40.1

Re: [PATCH] conf: Fix erroneous check of ip6->gw

[Stefano Brivio]

On Fri,  2 Jun 2023 15:02:02 +1000
David Gibson <david@gibson.dropbear.id.au> wrote:

> a7359f094898 ("conf: Don't exit if sourced default route has no gateway")
> was supposed to allow passt/pasta to run even if given a template interface
> which has no default gateway.  However a mistake in the patch means it
> still requires the gateway, but doesn't require a global address for the
> guest which we really do need.
> 
> This is one part (but not the only part) of the problem seen in
> https://bugs.passt.top/show_bug.cgi?id=50.
>
> Fixes: a7359f094898

Thanks! Applied with:

Reported-by: Justin Jereza <justinjereza@gmail.com>
Fixes: a7359f094898 ("conf: Don't exit if sourced default route has no gateway")
Link: https://bugs.passt.top/show_bug.cgi?id=50
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

If it helps (not that you need to care, really):
  git show -s --abbrev=12 --pretty=format:"Fixes: %h (\"%s\")" "${sha}"

or... scripts:
  https://lore.kernel.org/all/20190220205910.7bd7fd40@redhat.com/
  https://lore.kernel.org/all/20190220213729.49deb54f@redhat.com/

> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
>
> ---
>  conf.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/conf.c b/conf.c
> index d8414fe7..ffff235b 100644
> --- a/conf.c
> +++ b/conf.c
> @@ -708,7 +708,7 @@ static unsigned int conf_ip6(unsigned int ifi,
>  	if (MAC_IS_ZERO(mac))
>  		nl_link(0, ifi, mac, 0, 0);
>  
> -	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->gw) ||
> +	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->addr) ||
>  	    IN6_IS_ADDR_UNSPECIFIED(&ip6->addr_ll) ||
>  	    MAC_IS_ZERO(mac))
>  		return 0;

-- 
Stefano