[PATCH] huawei: add basic support for ME909u-521

[Dan Williams]

On Thu, 2016-09-15 at 18:57 +0200, Stefan Eichenberger wrote:
> The ME909u-512 does theoretically support the DHCP feature over AT
> but if
> this is done right after the NDISDUP command, it seems that the
> firmware
> has some trouble with it because the firmware will not attach the
> Ethernet header afterwards. This can be seen by doing a tcpdump while
> pinging e.g. 8.8.8.8. The request has a size of 98 Bytes, while the
> replies only have a size of 84 Bytes. The first 14 Bytes are missing
> which is exactly the size of the Ethernet header.
> 
> To reproduce this issue, I've tried the command sequence manually:
> mmcli -m 0 --command 'AT^NDISDUP=1,1,"gprs.swisscom.ch"'
> mmcli -m 0 --command "AT+CREG?"
> mmcli -m 0 --command "AT^NDISSTATQRY?"
> mmcli -m 0 --command "AT+CGREG?"
> mmcli -m 0 --command "AT^DHCP?"
> 
> The error appears in with this sequence
> 
> mmcli -m 0 --command 'AT^NDISDUP=1,1,"gprs.swisscom.ch"'
> mmcli -m 0 --command "AT+CREG?"
> mmcli -m 0 --command "AT^NDISSTATQRY?"
> mmcli -m 0 --command "AT+CGREG?"

Have you tested out how long the firmware needs before it can take the
AT^DHCP without problems?

Dan

> The error does not appear in this sequence
> 
> This commit applies to 1.6.0 and adds a udev option for this modem,
> which disables the DHCP over AT command feature.
> 
> Signed-off-by: Stefan Eichenberger <stefan.eichenberger at netmodule.com
> >
> ---
>  plugins/huawei/77-mm-huawei-net-port-types.rules |  3 ++
>  plugins/huawei/mm-broadband-bearer-huawei.c      | 50
> ++++++++++++++++++------
>  2 files changed, 42 insertions(+), 11 deletions(-)
> 
> diff --git a/plugins/huawei/77-mm-huawei-net-port-types.rules
> b/plugins/huawei/77-mm-huawei-net-port-types.rules
> index f60f1f8..d35f2d5 100644
> --- a/plugins/huawei/77-mm-huawei-net-port-types.rules
> +++ b/plugins/huawei/77-mm-huawei-net-port-types.rules
> @@ -6,6 +6,9 @@ ENV{ID_VENDOR_ID}!="12d1",
> GOTO="mm_huawei_port_types_end"
>  # MU609 does not support getportmode (crashes modem with default
> firmware)
>  ATTRS{idProduct}=="1573", ENV{ID_MM_HUAWEI_DISABLE_GETPORTMODE}="1"
>  
> +# MU909u does not support DHCP properly, it can happen that the
> Ethernet frames do not attach the Ethernet header afterwards.
> +ATTRS{idProduct}=="1573", ENV{ID_MM_HUAWEI_DISABLE_DHCP}="1"
> +
>  # Mark the modem and at port flags for ModemManager
>  SUBSYSTEMS=="usb", ATTRS{bInterfaceClass}=="ff",
> ATTRS{bInterfaceSubClass}=="01", ATTRS{bInterfaceProtocol}=="01",
> ENV{ID_MM_HUAWEI_MODEM_PORT}="1"
>  SUBSYSTEMS=="usb", ATTRS{bInterfaceClass}=="ff",
> ATTRS{bInterfaceSubClass}=="01", ATTRS{bInterfaceProtocol}=="02",
> ENV{ID_MM_HUAWEI_AT_PORT}="1"
> diff --git a/plugins/huawei/mm-broadband-bearer-huawei.c
> b/plugins/huawei/mm-broadband-bearer-huawei.c
> index 60a91e5..11782c3 100644
> --- a/plugins/huawei/mm-broadband-bearer-huawei.c
> +++ b/plugins/huawei/mm-broadband-bearer-huawei.c
> @@ -465,17 +465,34 @@ connect_3gpp_context_step (Connect3gppContext
> *ctx)
>                                         g_object_ref (ctx->self));
>          return;
>  
> -    case CONNECT_3GPP_CONTEXT_STEP_IP_CONFIG:
> -        mm_base_modem_at_command_full (ctx->modem,
> -                                       ctx->primary,
> -                                       "^DHCP?",
> -                                       3,
> -                                       FALSE,
> -                                       FALSE,
> -                                       NULL,
> -                                       (GAsyncReadyCallback)connect_
> dhcp_check_ready,
> -                                       g_object_ref (ctx->self));
> -        return;
> +    case CONNECT_3GPP_CONTEXT_STEP_IP_CONFIG: {
> +        GUdevClient *client;
> +        GUdevDevice *data_device;
> +
> +        // ME909u has a problem with DHCP over AT. If it's done
> right after NDSIDUP
> +        // the modem doesn't send the Ethernet header anymore which
> confuses the network stack
> +        client = g_udev_client_new (NULL);
> +        data_device = (g_udev_client_query_by_subsystem_and_name (
> +                           client,
> +                           "tty",
> +                           mm_port_get_device (&ctx->primary-
> >parent.parent)));
> +        if (!data_device || !g_udev_device_get_property_as_boolean
> (data_device, "ID_MM_HUAWEI_DISABLE_DHCP")) {
> +            mm_base_modem_at_command_full (ctx->modem,
> +                                           ctx->primary,
> +                                           "^DHCP?",
> +                                           3,
> +                                           FALSE,
> +                                           FALSE,
> +                                           NULL,
> +                                           (GAsyncReadyCallback)conn
> ect_dhcp_check_ready,
> +                                           g_object_ref (ctx-
> >self));
> +            return;
> +        }
> +
> +        mm_info("This device (%s) does not support DHCP over AT",
> mm_port_get_device (ctx->data));
> +        ctx->step ++;
> +        /* Fall down to the next step */
> +    }
>  
>      case CONNECT_3GPP_CONTEXT_STEP_LAST:
>          /* Clear context */
> @@ -489,6 +506,17 @@ connect_3gpp_context_step (Connect3gppContext
> *ctx)
>                      mm_bearer_connect_result_new (ctx->data, ctx-
> >ipv4_config, NULL),
>                      (GDestroyNotify)mm_bearer_connect_result_unref);
>              }
> +            else {
> +                MMBearerIpConfig *ipv4_config;
> +
> +                ipv4_config = mm_bearer_ip_config_new ();
> +                mm_bearer_ip_config_set_method (ipv4_config,
> MM_BEARER_IP_METHOD_DHCP);
> +                g_simple_async_result_set_op_res_gpointer (
> +                    ctx->result,
> +                    mm_bearer_connect_result_new (ctx->data,
> ipv4_config, NULL),
> +                    (GDestroyNotify)mm_bearer_connect_result_unref);
> +                g_object_unref (ipv4_config);
> +            }
>          }
>  
>          connect_3gpp_context_complete_and_free (ctx);