On Thu, Jul 09, 2015 at 02:57:57PM +0200, Eric Dumazet wrote: > On Thu, 2015-07-09 at 10:42 +0200, Phil Sutter wrote: > > Reconsidering my commit 20462155 "net: inet_diag: export IPV6_V6ONLY > > sockopt", I am not happy with the limitations it causes for socket > > analysing code in userspace. Exporting the value only if it is set makes > > it hard for userspace to decide whether the option is not set or the > > kernel does not support exporting the option at all. > > > > From an auditor's perspective, the interesting question for AF_INET6 > > sockets is: "Does it NOT have IPV6_V6ONLY set?" Because it is the > > unexpected case. This patch allows to answer this question reliably. > > > > Signed-off-by: Phil Sutter <p...@nwl.cc> > > Cc: Eric Dumazet <eduma...@google.com> > > --- > > net/ipv4/inet_diag.c | 3 +-- > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c > > index 9bc2667..e622d2e 100644 > > --- a/net/ipv4/inet_diag.c > > +++ b/net/ipv4/inet_diag.c > > @@ -152,8 +152,7 @@ int inet_sk_diag_fill(struct sock *sk, struct > > inet_connection_sock *icsk, > > inet6_sk(sk)->tclass) < 0) > > goto errout; > > > > - if (ipv6_only_sock(sk) && > > - nla_put_u8(skb, INET_DIAG_SKV6ONLY, 1)) > > + if (nla_put_u8(skb, INET_DIAG_SKV6ONLY, ipv6_only_sock(sk))) > > goto errout; > > } > > #endif > > Okay, I guess you don't dump millions of sockets.
I hope not, although I don't know what tools other than ss use inet_diag. > Can you remind me why this attribute is useful for non listening > sockets ? Indeed, it isn't. > It looks you are interested to know if a _listener_ is v6 only or not. Is it possible to select that in a generic way? If I didn't misread the code, 'ss -l' filters them out locally. It looks like sk->sk_state can be used to determine that, but it seems to be used for TCP states only? Or is the value 10 (TCP_LISTEN) used for e.g. UDP as well? Thanks, Phil -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
