1 files changed, 61 insertions, 1 deletions

diff --git a/src/libembim/embim-device.c b/src/libembim/embim-device.c
index 68852cf..740b84e 100644
--- a/src/libembim/embim-device.c
+++ b/src/libembim/embim-device.c
@@ -32,6 +32,10 @@
 #include <fcntl.h>
 #include <unistd.h>
 
+#include <sys/ioctl.h>
+#define IOCTL_WDM_MAX_COMMAND _IOR('H', 0xA0, uint16_t)
+#define FALLBACK_MAX_CONTROL_TRANSFER 4096
+
 #include "embim-device.h"
 
 /*****************************************************************************/
@@ -42,6 +46,8 @@ struct embim_device_s {
     char *path;
     /* Open device FD */
     int fd;
+    /* Transaction ID */
+    uint32_t transaction_id;
     /* Registered indication callbacks */
     struct indication_s *indications;
     size_t               indications_n;
@@ -54,6 +60,7 @@ static void notify_indication   (embim_device_t *self,
                                  const uint8_t  *indication);
 
 /*****************************************************************************/
+/* Basic device creation/destruction */
 
 embim_device_t *
 embim_device_new (const char *path)
@@ -97,6 +104,18 @@ embim_device_free (embim_device_t *self)
 }
 
 /*****************************************************************************/
+/* MBIM write */
+
+embim_status_e
+embim_device_write (embim_device_t *self,
+                    const uint8_t  *message,
+                    size_t          message_size)
+{
+
+
+}
+
+/*****************************************************************************/
 /* MBIM open */
 
 embim_status_e
@@ -107,14 +126,35 @@ embim_device_open (embim_device_t *self)
         return EMBIM_STATUS_SUCCESS;
 
     self->fd = open (self->path, O_RDWR | FD_CLOEXEC);
-    if (self->fd < 0)
+    if (self->fd < 0) {
+        /* Not having enough privileges is a very common error here. */
+        if (errno == EACCESS)
+            return EMBIM_STATUS_ERROR_UNAUTHORIZED;
         return EMBIM_STATUS_ERROR_GENERIC;
+    }
+
+    /* Query message size */
+    if (ioctl (self->fd, IOCTL_WDM_MAX_COMMAND, &self->max_control_transfer) < 0)
+        /* Fallback to a default value */
+        self->max_control_transfer = FALLBACK_MAX_CONTROL_TRANSFER;
 
     notify_indication (self, NULL);
 
     return EMBIM_STATUS_SUCCESS;
 }
 
+int
+embim_device_get_fd (embim_device_t *self)
+{
+    return self->fd;
+}
+
+uint16_t
+embim_device_get_max_control_transfer (embim_device_t *self)
+{
+    return self->max_control_transfer;
+}
+
 /*****************************************************************************/
 /* MBIM close */
 
@@ -125,10 +165,30 @@ embim_device_close (embim_device_t *self)
         close (self->fd);
         self->fd = -1;
     }
+
     return EMBIM_STATUS_SUCCESS;
 }
 
 /*****************************************************************************/
+/* Transaction ID management */
+
+static uint32_t
+get_next_transaction_id (embim_device_t *self)
+{
+    uint32_t next;
+
+    next = self->transaction_id;
+
+    if (self->transaction_id == (uint32_t) 0xFFFFFFFF)
+        /* Reset! */
+        self->priv->transaction_id = 0x01;
+    else
+        self->priv->transaction_id++;
+
+    return next;
+}
+
+/*****************************************************************************/
 /* Registered callbacks for indications */
 
 struct indication_s {