Fix is_ipv6 in case of tap interface.

While checking a packet on a TAP interface, is_ipv_X() in proto.c
insist that the ethertype must be OPENVPN_ETH_P_IPV4, even if
the protocol is IPv6. So the protocol never match, and, thus,
mssfix doesn't work for IPv6 on TAP interface. Fix that.

Signed-off-by: Dmitrij Tejblum <dt@yandex.ru>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <1391873629-14388-1-git-send-email-dt@yandex.ru>
URL: http://article.gmane.org/gmane.network.openvpn.devel/8259
Signed-off-by: Gert Doering <gert@greenie.muc.de>
Conditionalize calls to print_default_gateway on !ENABLE_SMALL

Calls to print_default_gateway() depended on #ifdef ENABLE_DEBUG, but
the actual function wasn't compiled in #ifdef ENABLE_SMALL, so the
combination "configure --enable-small --enable-debug" didn't work. Fix.

Fix trac #397

Signed-off-by: Gert Doering <gert@greenie.muc.de>
Acked-by: Steffan Karger <steffan.karger@fox-it.com>
Message-Id: <1398805779-29376-1-git-send-email-gert@greenie.muc.de>
URL: http://article.gmane.org/gmane.network.openvpn.devel/8670