For AF_INET6 sockets, the value of struct ipv6_pinfo.ipv6only is exported to userspace. It indicates whether a socket bound to in6addr_any listens on IPv4 as well as IPv6. Since the socket is natively IPv6, it is not listed by e.g. 'ss -l -4'.
This patch is accompanied by an appropriate one for iproute2 to enable the additional information in 'ss -e'. Signed-off-by: Phil Sutter <p...@nwl.cc> --- Changes since v1: - Commit message corrected. - Patch based on current net-next.git. - Eric's superior solution implemented. --- include/uapi/linux/inet_diag.h | 3 ++- net/ipv4/inet_diag.c | 4 ++++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/inet_diag.h b/include/uapi/linux/inet_diag.h index b629fc5..68a1f71 100644 --- a/include/uapi/linux/inet_diag.h +++ b/include/uapi/linux/inet_diag.h @@ -112,9 +112,10 @@ enum { INET_DIAG_SHUTDOWN, INET_DIAG_DCTCPINFO, INET_DIAG_PROTOCOL, /* response attribute only */ + INET_DIAG_SKV6ONLY, }; -#define INET_DIAG_MAX INET_DIAG_PROTOCOL +#define INET_DIAG_MAX INET_DIAG_SKV6ONLY /* INET_DIAG_MEM */ diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index 21985d8..653564d 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -151,6 +151,10 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk, if (nla_put_u8(skb, INET_DIAG_TCLASS, inet6_sk(sk)->tclass) < 0) goto errout; + + if (ipv6_only_sock(sk) && + nla_put_u8(skb, INET_DIAG_SKV6ONLY, 1)) + goto errout; } #endif -- 2.1.2 -- 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