Hi,
On Wed, Nov 10, 2021 at 6:01 AM Lev Stipakov <lstipa...@gmail.com> wrote:
> From: Lev Stipakov <l...@openvpn.net>
>
> When /30 subnet is pushed (like in the case of OpenVPN Cloud),
> DHCP server address is calculated to be the same as local address,
> which causes collision and therefore connection is not established.
>
> To fix that, use openvpn3 approach, which sets DHCP server
> address to a network address for small subnets
>
> Signed-off-by: Lev Stipakov <l...@openvpn.net>
> ---
> src/openvpn/tun.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
> index 28f803ec..994e3751 100644
> --- a/src/openvpn/tun.c
> +++ b/src/openvpn/tun.c
> @@ -6363,7 +6363,9 @@ tuntap_dhcp_mask(const struct tuntap *tt, const char
> *device_guid)
> }
> else
> {
> - ep[2] = dhcp_masq_addr(tt->local, tt->remote_netmask, -1);
> + int prefix_len = netmask_to_netbits2(tt->adapter_netmask);
> + /* use network address as DHCP server for small subnets,
> otherwise last address before broadcast */
> + ep[2] = dhcp_masq_addr(tt->local, tt->remote_netmask,
> prefix_len < 28 ? -1 : 0);
> }
> }
> else
> --
Why not just use 0 offset always? Perpetuating this dance of 0 offset in
some cases, -1 otherwise is not a way forward. Also see my patch from 2015
that never got any traction. I have lost touch with the context, so, I'm
not sure whether this addresses the same (apart from code changes) or
something related.
https://sourceforge.net/p/openvpn/mailman/openvpn-devel/thread/1449454660-20050-1-git-send-email-selva.nair%40gmail.com/#msg34674818
Also:
https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg13413.html
and other messages in that thread.
Selva
_______________________________________________
Openvpn-devel mailing list
Openvpn-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/openvpn-devel
