gsm: add preliminary USSD support (bgo #590798)

We currently convert to and from the modem's set charset and always pass
'15' as the data coding scheme. Passing the correct data coding scheme
as third argument to CUSD only upsets the network. This contradicts 3GPP
TS 23.038. Other tools like gsm-ussd handle it the same way.

Network responses that require further actions are not yet implemented.

(some fixes and cleanups by Dan Williams)

1 files changed, 232 insertions, 1 deletions

diff --git a/src/mm-generic-gsm.c b/src/mm-generic-gsm.c
index 2ffa8cfc..20e26c25 100644
--- a/src/mm-generic-gsm.c
+++ b/src/mm-generic-gsm.c
@@ -25,6 +25,7 @@
 #include "mm-modem-gsm-card.h"
 #include "mm-modem-gsm-network.h"
 #include "mm-modem-gsm-sms.h"
+#include "mm-modem-gsm-ussd.h"
 #include "mm-modem-simple.h"
 #include "mm-errors.h"
 #include "mm-callback-info.h"
@@ -41,6 +42,7 @@ static void modem_init (MMModem *modem_class);
 static void modem_gsm_card_init (MMModemGsmCard *gsm_card_class);
 static void modem_gsm_network_init (MMModemGsmNetwork *gsm_network_class);
 static void modem_gsm_sms_init (MMModemGsmSms *gsm_sms_class);
+static void modem_gsm_ussd_init (MMModemGsmUssd *gsm_ussd_class);
 static void modem_simple_init (MMModemSimple *class);
 static void modem_location_init (MMModemLocation *class);
 
@@ -50,6 +52,7 @@ G_DEFINE_TYPE_EXTENDED (MMGenericGsm, mm_generic_gsm, MM_TYPE_MODEM_BASE, 0,
                         G_IMPLEMENT_INTERFACE (MM_TYPE_MODEM_GSM_NETWORK, modem_gsm_network_init)
                         G_IMPLEMENT_INTERFACE (MM_TYPE_MODEM_GSM_SMS, modem_gsm_sms_init)
                         G_IMPLEMENT_INTERFACE (MM_TYPE_MODEM_LOCATION, modem_location_init)
+                        G_IMPLEMENT_INTERFACE (MM_TYPE_MODEM_GSM_USSD, modem_gsm_ussd_init)
                         G_IMPLEMENT_INTERFACE (MM_TYPE_MODEM_SIMPLE, modem_simple_init))
 
 #define MM_GENERIC_GSM_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), MM_TYPE_GENERIC_GSM, MMGenericGsmPrivate))
@@ -110,6 +113,8 @@ typedef struct {
     guint32 loc_caps;
     gboolean loc_enabled;
     gboolean loc_signal;
+
+    MMModemGsmUssdState ussd_state;
 } MMGenericGsmPrivate;
 
 static void get_registration_status (MMAtSerialPort *port, MMCallbackInfo *info);
@@ -3603,7 +3608,7 @@ sms_send_done (MMAtSerialPort *port,
 }
 
 static void
-sms_send (MMModemGsmSms *modem, 
+sms_send (MMModemGsmSms *modem,
           const char *number,
           const char *text,
           const char *smsc,
@@ -3669,6 +3674,180 @@ mm_generic_gsm_get_best_at_port (MMGenericGsm *self, GError **error)
 }
 
 /*****************************************************************************/
+/* MMModemGsmUssd interface */
+
+static void
+ussd_update_state (MMGenericGsm *self, MMModemGsmUssdState new_state)
+{
+    MMGenericGsmPrivate *priv = MM_GENERIC_GSM_GET_PRIVATE (self);
+
+    if (new_state != priv->ussd_state) {
+        priv->ussd_state = new_state;
+        g_object_notify (G_OBJECT (self), MM_MODEM_GSM_USSD_STATE);
+    }
+}
+
+static void
+ussd_initiate_done (MMAtSerialPort *port,
+                    GString *response,
+                    GError *error,
+                    gpointer user_data)
+{
+    MMCallbackInfo *info = (MMCallbackInfo *) user_data;
+    MMGenericGsmPrivate *priv;
+    gint status;
+    gboolean parsed = FALSE;
+    MMModemGsmUssdState ussd_state = MM_MODEM_GSM_USSD_STATE_IDLE;
+    const char *str, *start = NULL, *end = NULL;
+    char *reply = NULL, *converted;
+
+    if (error) {
+        info->error = g_error_copy (error);
+        goto done;
+    }
+
+    priv = MM_GENERIC_GSM_GET_PRIVATE (info->modem);
+    ussd_state = priv->ussd_state;
+
+    str = mm_strip_tag (response->str, "+CUSD:");
+    if (!str || !isdigit (*str))
+        goto done;
+
+    status = g_ascii_digit_value (*str);
+    switch (status) {
+    case 0: /* no further action required */
+        ussd_state = MM_MODEM_GSM_USSD_STATE_IDLE;
+        break;
+    case 1: /* Not an error but not yet implemented */
+        info->error = g_error_new (MM_MODEM_ERROR,
+                                   MM_MODEM_ERROR_GENERAL,
+                                   "Further action required.");
+        ussd_state = MM_MODEM_GSM_USSD_STATE_USER_RESPONSE;
+        break;
+    case 2:
+        info->error = g_error_new (MM_MODEM_ERROR,
+                                   MM_MODEM_ERROR_GENERAL,
+                                   "USSD terminated by network.");
+        ussd_state = MM_MODEM_GSM_USSD_STATE_IDLE;
+        break;
+    case 4:
+        info->error = g_error_new (MM_MODEM_ERROR,
+                                   MM_MODEM_ERROR_GENERAL,
+                                   "Operiation not supported.");
+        ussd_state = MM_MODEM_GSM_USSD_STATE_IDLE;
+        break;
+    default:
+        info->error = g_error_new (MM_MODEM_ERROR,
+                                   MM_MODEM_ERROR_GENERAL,
+                                   "Unknown USSD reply %d", status);
+        ussd_state = MM_MODEM_GSM_USSD_STATE_IDLE;
+        break;
+    }
+    if (info->error)
+        goto done;
+
+    /* look for the reply */
+    if ((start = strchr (str, '"')) && (end = strrchr (str, '"')) && (start != end))
+        reply = g_strndup (start + 1, end - start -1);
+
+    if (reply) {
+        /* look for the reply data coding scheme */
+        if (mm_options_debug ()) {
+            if ((start = strrchr (end, ',')) != NULL)
+                g_debug ("USSD data coding scheme %d", atoi (start + 1));
+        }
+
+        converted = mm_modem_charset_hex_to_utf8 (reply, priv->cur_charset);
+        mm_callback_info_set_result (info, converted, g_free);
+        parsed = TRUE;
+        g_free (reply);
+    }
+
+done:
+    if (!parsed && !info->error) {
+        info->error = g_error_new (MM_MODEM_ERROR,
+                                   MM_MODEM_ERROR_GENERAL,
+                                   "Could not parse USSD reply '%s'",
+                                   response->str);
+    }
+    mm_callback_info_schedule (info);
+
+    if (info->modem)
+        ussd_update_state (MM_GENERIC_GSM (info->modem), ussd_state);
+}
+
+static void
+ussd_initiate (MMModemGsmUssd *modem,
+               const char *command,
+               MMModemStringFn callback,
+               gpointer user_data)
+{
+    MMCallbackInfo *info;
+    char *atc_command;
+    char *hex;
+    GByteArray *ussd_command = g_byte_array_new();
+    MMGenericGsmPrivate *priv = MM_GENERIC_GSM_GET_PRIVATE (modem);
+    MMAtSerialPort *port;
+
+    info = mm_callback_info_string_new (MM_MODEM (modem), callback, user_data);
+
+    port = mm_generic_gsm_get_best_at_port (MM_GENERIC_GSM (modem), &info->error);
+    if (!port) {
+        mm_callback_info_schedule (info);
+        return;
+    }
+
+    /* encode to cur_charset */
+    g_warn_if_fail (mm_modem_charset_byte_array_append (ussd_command, command, FALSE, priv->cur_charset));
+    /* convert to hex representation */
+    hex = utils_bin2hexstr (ussd_command->data, ussd_command->len);
+    g_byte_array_free (ussd_command, TRUE);
+    atc_command = g_strdup_printf ("+CUSD=1,\"%s\",15", hex);
+    g_free (hex);
+
+    mm_at_serial_port_queue_command (port, atc_command, 10, ussd_initiate_done, info);
+    g_free (atc_command);
+
+    ussd_update_state (MM_GENERIC_GSM (modem), MM_MODEM_GSM_USSD_STATE_ACTIVE);
+}
+
+static void
+ussd_cancel_done (MMAtSerialPort *port,
+                  GString *response,
+                  GError *error,
+                  gpointer user_data)
+{
+    MMCallbackInfo *info = (MMCallbackInfo *) user_data;
+
+    if (error)
+        info->error = g_error_copy (error);
+
+    mm_callback_info_schedule (info);
+
+    if (info->modem)
+        ussd_update_state (MM_GENERIC_GSM (info->modem), MM_MODEM_GSM_USSD_STATE_IDLE);
+}
+
+static void
+ussd_cancel (MMModemGsmUssd *modem,
+             MMModemFn callback,
+             gpointer user_data)
+{
+    MMCallbackInfo *info;
+    MMAtSerialPort *port;
+
+    info = mm_callback_info_new (MM_MODEM (modem), callback, user_data);
+
+    port = mm_generic_gsm_get_best_at_port (MM_GENERIC_GSM (modem), &info->error);
+    if (!port) {
+        mm_callback_info_schedule (info);
+        return;
+    }
+
+    mm_at_serial_port_queue_command (port, "+CUSD=2", 10, ussd_cancel_done, info);
+}
+
+/*****************************************************************************/
 /* MMModemSimple interface */
 
 typedef enum {
@@ -4309,6 +4488,13 @@ modem_gsm_sms_init (MMModemGsmSms *class)
 }
 
 static void
+modem_gsm_ussd_init (MMModemGsmUssd *class)
+{
+    class->initiate = ussd_initiate;
+    class->cancel = ussd_cancel;
+}
+
+static void
 modem_simple_init (MMModemSimple *class)
 {
     class->connect = simple_connect;
@@ -4354,6 +4540,21 @@ mm_generic_gsm_init (MMGenericGsm *self)
                                                     NULL,
                                                     MM_MODEM_LOCATION_DBUS_INTERFACE);
 
+    mm_properties_changed_signal_register_property (G_OBJECT (self),
+                                                    MM_MODEM_GSM_USSD_STATE,
+                                                    "State",
+                                                    MM_MODEM_GSM_USSD_DBUS_INTERFACE);
+
+    mm_properties_changed_signal_register_property (G_OBJECT (self),
+                                                    MM_MODEM_GSM_USSD_NETWORK_NOTIFICATION,
+                                                    "NetworkNotification",
+                                                    MM_MODEM_GSM_USSD_DBUS_INTERFACE);
+
+    mm_properties_changed_signal_register_property (G_OBJECT (self),
+                                                    MM_MODEM_GSM_USSD_NETWORK_REQUEST,
+                                                    "NetworkRequest",
+                                                    MM_MODEM_GSM_USSD_DBUS_INTERFACE);
+
     g_signal_connect (self, "notify::" MM_MODEM_STATE,
                       G_CALLBACK (modem_state_changed), NULL);
 }
@@ -4377,6 +4578,9 @@ set_property (GObject *object, guint prop_id,
     case MM_GENERIC_GSM_PROP_LOC_ENABLED:
     case MM_GENERIC_GSM_PROP_LOC_SIGNAL:
     case MM_GENERIC_GSM_PROP_LOC_LOCATION:
+    case MM_GENERIC_GSM_PROP_USSD_STATE:
+    case MM_GENERIC_GSM_PROP_USSD_NETWORK_REQUEST:
+    case MM_GENERIC_GSM_PROP_USSD_NETWORK_NOTIFICATION:
         break;
     default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
@@ -4384,6 +4588,24 @@ set_property (GObject *object, guint prop_id,
     }
 }
 
+static const char *
+ussd_state_to_string (MMModemGsmUssdState ussd_state)
+{
+    switch (ussd_state) {
+    case MM_MODEM_GSM_USSD_STATE_IDLE:
+        return "idle";
+    case MM_MODEM_GSM_USSD_STATE_ACTIVE:
+        return "active";
+    case MM_MODEM_GSM_USSD_STATE_USER_RESPONSE:
+        return "user-response";
+    default:
+        break;
+    }
+
+    g_warning ("Unknown GSM USSD state %d", ussd_state);
+    return "unknown";
+}
+
 static void
 get_property (GObject *object, guint prop_id,
               GValue *value, GParamSpec *pspec)
@@ -4457,6 +4679,15 @@ get_property (GObject *object, guint prop_id,
             locations = g_hash_table_new (g_direct_hash, g_direct_equal);
         g_value_take_boxed (value, locations);
         break;
+    case MM_GENERIC_GSM_PROP_USSD_STATE:
+        g_value_set_string (value, ussd_state_to_string (priv->ussd_state));
+        break;
+    case MM_GENERIC_GSM_PROP_USSD_NETWORK_REQUEST:
+        g_value_set_string (value, "");
+        break;
+    case MM_GENERIC_GSM_PROP_USSD_NETWORK_NOTIFICATION:
+        g_value_set_string (value, "");
+        break;
     default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
         break;