Signed-off-by: Christopher Schenk <csch...@mail.uni-paderborn.de>
---
include/openvpn-msg.h | 8 ++++
src/openvpn/tun.c | 89 +++++++++++++++++++++++++++++++++++
src/openvpnserv/interactive.c | 31 ++++++++++++
3 files changed, 128 insertions(+)
diff --git a/include/openvpn-msg.h b/include/openvpn-msg.h
index 66177a21..10cd68ac 100644
--- a/include/openvpn-msg.h
+++ b/include/openvpn-msg.h
@@ -39,6 +39,7 @@ typedef enum {
msg_del_block_dns,
msg_register_dns,
msg_enable_dhcp,
+ msg_set_mtu,
} message_type_t;
typedef struct {
@@ -117,4 +118,11 @@ typedef struct {
interface_t iface;
} enable_dhcp_message_t;
+typedef struct {
+ message_header_t header;
+ interface_t iface;
+ short family;
+ int mtu;
+} set_mtu_message_t;
+
#endif /* ifndef OPENVPN_MSG_H_ */
diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
index 48a8fdf7..3895e421 100644
--- a/src/openvpn/tun.c
+++ b/src/openvpn/tun.c
@@ -69,6 +69,10 @@ static void netsh_ifconfig(const struct tuntap_options
*to,
const in_addr_t netmask,
const unsigned int flags);
+static void windows_set_mtu(const int iface_index,
+ const short family,
+ const int mtu);
+
static void netsh_set_dns6_servers(const struct in6_addr *addr_list,
const int addr_len,
const char *flex_name);
@@ -201,6 +205,47 @@ out:
return ret;
}
+static bool
+do_set_mtu_service(const struct tuntap *tt, const short family, const int
mtu)
+{
+ DWORD len;
+ bool ret = false;
+ ack_message_t ack;
+ struct gc_arena gc = gc_new();
+ HANDLE pipe = tt->options.msg_channel;
+ const char *family_name = (family == AF_INET6) ? "IPv6" : "IPv4";
+ set_mtu_message_t mtu_msg = {
+ .header = {
+ msg_set_mtu,
+ sizeof(set_mtu_message_t),
+ 0
+ },
+ .iface = {.index = tt->adapter_index,.name = tt->actual_name },
+ .mtu = mtu,
+ .family = family
+ };
+
+ if (!send_msg_iservice(pipe, &mtu_msg, sizeof(mtu_msg), &ack,
"Set_mtu"))
+ {
+ goto out;
+ }
+
+ if (ack.error_number != NO_ERROR)
+ {
+ msg(M_NONFATAL, "TUN: setting %s mtu using service failed: %s
[status=%u if_index=%d]",
+ family_name, strerror_win32(ack.error_number, &gc),
ack.error_number, mtu_msg.iface.index);
+ else
+ {
+ msg(M_INFO, "%s MTU set to %d on interface %d using service",
family_name, mtu, mtu_msg.iface.index);
+ ret = true;
+ }
+
+out:
+ gc_free(&gc);
+ return ret;
+}
+
#endif /* ifdef _WIN32 */
#ifdef TARGET_SOLARIS
@@ -984,6 +1029,7 @@ do_ifconfig_ipv6(struct tuntap *tt, const char
*ifname, int tun_mtu,
{
do_address_service(true, AF_INET6, tt);
do_dns6_service(true, tt);
+ do_set_mtu_service(tt, AF_INET6, tun_mtu);
}
else
{
@@ -1000,6 +1046,7 @@ do_ifconfig_ipv6(struct tuntap *tt, const char
*ifname, int tun_mtu,
netsh_command(&argv, 4, M_FATAL);
/* set ipv6 dns servers if any are specified */
netsh_set_dns6_servers(tt->options.dns6, tt->options.dns6_len,
ifname);
+ windows_set_mtu(tt->adapter_index, AF_INET6, tun_mtu);
}
/* explicit route needed */
@@ -1394,6 +1441,14 @@ do_ifconfig_ipv4(struct tuntap *tt, const char
*ifname, int tun_mtu,
break;
}
+ if (tt->options.msg_channel)
+ {
+ do_set_mtu_service(tt, AF_INET, tun_mtu);
+ }
+ else
+ {
+ windows_set_mtu(tt->adapter_index, AF_INET, tun_mtu);
+ }
}
#else /* if defined(TARGET_LINUX) */
@@ -5236,6 +5291,40 @@ out:
return ret;
}
+static void
+windows_set_mtu(const int iface_index, const short family,
+ const int mtu)
+{
+ DWORD err = 0;
+ struct gc_arena gc = gc_new();
+ MIB_IPINTERFACE_ROW ipiface;
+ InitializeIpInterfaceEntry(&ipiface);
+ const char *family_name = (family == AF_INET6) ? "IPv6" : "IPv4";
+ ipiface.Family = family;
+ ipiface.InterfaceIndex = iface_index;
+ err = GetIpInterfaceEntry(&ipiface);
+ if (err == NO_ERROR)
+ {
+ if (family == AF_INET)
+ {
+ ipiface.SitePrefixLength = 0;
+ }
+ ipiface.NlMtu = mtu;
+ err = SetIpInterfaceEntry(&ipiface);
+ }
+
+ if (err != NO_ERROR)
+ {
+ msg(M_WARN, "TUN: Setting %s mtu failed: %s [status=%u
if_index=%d]",
+ family_name, strerror_win32(err, &gc), err, iface_index);
+ }
+ else
+ {
+ msg(M_INFO, "Successfully set %s mtu on interface %d",
family_name, iface_index);
+ }
+}
+
+
/*
* Return a TAP name for netsh commands.
*/
diff --git a/src/openvpnserv/interactive.c b/src/openvpnserv/interactive.c
index 623c3ff7..c24cb22b 100644
--- a/src/openvpnserv/interactive.c
+++ b/src/openvpnserv/interactive.c
@@ -1198,6 +1198,29 @@ HandleEnableDHCPMessage(const enable_dhcp_message_t
*dhcp)
return err;
}
+static DWORD
+HandleMTUMessage(const set_mtu_message_t *mtu)
+{
+ DWORD err = 0;
+ MIB_IPINTERFACE_ROW ipiface;
+ InitializeIpInterfaceEntry(&ipiface);
+ ipiface.Family = mtu->family;
+ ipiface.InterfaceIndex = mtu->iface.index;
+ err = GetIpInterfaceEntry(&ipiface);
+ if (err != NO_ERROR)
+ {
+ return err;
+ }
+ if (mtu->family == AF_INET)
+ {
+ ipiface.SitePrefixLength = 0;
+ }
+ ipiface.NlMtu = mtu->mtu;
+
+ err = SetIpInterfaceEntry(&ipiface);
+ return err;
+}
+
static VOID
HandleMessage(HANDLE pipe, DWORD bytes, DWORD count, LPHANDLE events,
undo_lists_t *lists)
{
@@ -1210,6 +1233,7 @@ HandleMessage(HANDLE pipe, DWORD bytes, DWORD count,
LPHANDLE events, undo_lists
block_dns_message_t block_dns;
dns_cfg_message_t dns;
enable_dhcp_message_t dhcp;
+ set_mtu_message_t mtu;
} msg;
ack_message_t ack = {
.header = {
@@ -1277,6 +1301,13 @@ HandleMessage(HANDLE pipe, DWORD bytes, DWORD
count, LPHANDLE events, undo_lists
}
break;
+ case msg_set_mtu:
+ if (msg.header.size == sizeof(msg.mtu))
+ {
+ ack.error_number = HandleMTUMessage(&msg.mtu);
+ }
+ break;
+
default:
ack.error_number = ERROR_MESSAGE_TYPE;
MsgToEventLog(MSG_FLAGS_ERROR, TEXT("Unknown message type
%d"), msg.header.type);
