sock: don't enable netstamp for af_unix sockets (080a270f) · Commits · 戴 / test

netstamp_needed is toggled for all socket families if they request timestamping. But some protocols don't need the lower-layer timestamping code at all. This patch starts disabling it for af-unix. E.g. systemd enables timestamping during boot-up on the journald af-unix sockets, thus causing the system to globally enable timestamping in the lower networking stack. Still, it is very probable that timestamping gets activated, by e.g. dhclient or various NTP implementations. Reported-by:

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

Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by:

Eric Dumazet <edumazet@google.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/core/sock.c

+17 −3

Original line number	Diff line number	Diff line
		@@ -422,13 +422,25 @@ static void sock_warn_obsolete_bsdism(const char *name)
		}
		}

		static bool sock_needs_netstamp(const struct sock *sk)
		{
		switch (sk->sk_family) {
		case AF_UNSPEC:
		case AF_UNIX:
		return false;
		default:
		return true;
		}
		}

		#define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) \| (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))

		static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
		{
		if (sk->sk_flags & flags) {
		sk->sk_flags &= ~flags;
		if (!(sk->sk_flags & SK_FLAGS_TIMESTAMP))
		if (sock_needs_netstamp(sk) &&
		!(sk->sk_flags & SK_FLAGS_TIMESTAMP))
		net_disable_timestamp();
		}
		}
		@@ -1582,7 +1594,8 @@ struct sock sk_clone_lock(const struct sock sk, const gfp_t priority)
		if (newsk->sk_prot->sockets_allocated)
		sk_sockets_allocated_inc(newsk);

		if (newsk->sk_flags & SK_FLAGS_TIMESTAMP)
		if (sock_needs_netstamp(sk) &&
		newsk->sk_flags & SK_FLAGS_TIMESTAMP)
		net_enable_timestamp();
		}
		out:
		@@ -2510,7 +2523,8 @@ void sock_enable_timestamp(struct sock *sk, int flag)
		* time stamping, but time stamping might have been on
		* already because of the other one
		*/
		if (!(previous_flags & SK_FLAGS_TIMESTAMP))
		if (sock_needs_netstamp(sk) &&
		!(previous_flags & SK_FLAGS_TIMESTAMP))
		net_enable_timestamp();
		}
		}

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