qmi-codegen: handle variable-sized string length prefix fields

Most string lengths are UINT8, but some (WDS Get Current Settings
PCSCF Domain Name List, for example) are UINT16.

3 files changed, 54 insertions, 21 deletions

diff --git a/build-aux/qmi-codegen/VariableString.py b/build-aux/qmi-codegen/VariableString.py
index 02f827b..5be84e2 100644
--- a/build-aux/qmi-codegen/VariableString.py
+++ b/build-aux/qmi-codegen/VariableString.py
@@ -42,7 +42,7 @@ class VariableString(Variable):
             self.is_fixed_size = True
             # Fixed-size strings
             self.needs_dispose = False
-            self.length_prefix = False
+            self.length_prefix_size = 0
             self.fixed_size = dictionary['fixed-size']
             self.max_size = ''
         else:
@@ -51,7 +51,15 @@ class VariableString(Variable):
             self.needs_dispose = True
             # Strings which are given as the full value of a TLV will NOT have a
             # length prefix
-            self.length_prefix = False if 'type' in dictionary and dictionary['type'] == 'TLV' else True
+            if 'type' in dictionary and dictionary['type'] == 'TLV':
+                self.length_prefix_size = 0
+            elif 'length-prefix-size' in dictionary:
+                self.length_prefix_size = dictionary['length-prefix-size']
+                if self.length_prefix_size not in ['8', '16']:
+                    raise ValueError('Invalid length prefix size %s: not 8 or 16' % self.length_prefix_size)
+            else:
+                # Default to UINT8
+                self.length_prefix_size = 8
             self.fixed_size = ''
             self.max_size = dictionary['max-size'] if 'max-size' in dictionary else ''
 
@@ -76,14 +84,14 @@ class VariableString(Variable):
                 '${lp}    &${variable_name}[0]);\n'
                 '${lp}${variable_name}[${fixed_size}] = \'\\0\';\n')
         else:
-            translations['length_prefix'] = 'TRUE' if self.length_prefix else 'FALSE'
+            translations['length_prefix_size'] = self.length_prefix_size
             translations['max_size'] = self.max_size if self.max_size != '' else '0'
             template = (
                 '${lp}/* Read the string variable from the buffer */\n'
                 '${lp}qmi_utils_read_string_from_buffer (\n'
                 '${lp}    &${buffer_name},\n'
                 '${lp}    &${buffer_len},\n'
-                '${lp}    ${length_prefix},\n'
+                '${lp}    ${length_prefix_size},\n'
                 '${lp}    ${max_size},\n'
                 '${lp}    &(${variable_name}));\n')
 
@@ -109,13 +117,13 @@ class VariableString(Variable):
                 '${lp}    ${fixed_size},\n'
                 '${lp}    ${variable_name});\n')
         else:
-            translations['length_prefix'] = 'TRUE' if self.length_prefix else 'FALSE'
+            translations['length_prefix_size'] = self.length_prefix_size
             template = (
                 '${lp}/* Write the string variable to the buffer */\n'
                 '${lp}qmi_utils_write_string_to_buffer (\n'
                 '${lp}    &${buffer_name},\n'
                 '${lp}    &${buffer_len},\n'
-                '${lp}    ${length_prefix},\n'
+                '${lp}    ${length_prefix_size},\n'
                 '${lp}    ${variable_name});\n')
 
         f.write(string.Template(template).substitute(translations))
@@ -149,7 +157,7 @@ class VariableString(Variable):
                 '${lp}    g_string_append_printf (${printable}, "%s", tmp);\n'
                 '${lp}}\n')
         else:
-            translations['length_prefix'] = 'TRUE' if self.length_prefix else 'FALSE'
+            translations['length_prefix_size'] = self.length_prefix_size
             translations['max_size'] = self.max_size if self.max_size != '' else '0'
             template = (
                 '\n'
@@ -160,7 +168,7 @@ class VariableString(Variable):
                 '${lp}    qmi_utils_read_string_from_buffer (\n'
                 '${lp}        &${buffer_name},\n'
                 '${lp}        &${buffer_len},\n'
-                '${lp}        ${length_prefix},\n'
+                '${lp}        ${length_prefix_size},\n'
                 '${lp}        ${max_size},\n'
                 '${lp}        &tmp);\n'
                 '\n'
diff --git a/libqmi-glib/qmi-utils.c b/libqmi-glib/qmi-utils.c
index 8eba462..4f0b292 100644
--- a/libqmi-glib/qmi-utils.c
+++ b/libqmi-glib/qmi-utils.c
@@ -360,26 +360,37 @@ qmi_utils_write_sized_guint_to_buffer (guint8  **buffer,
 void
 qmi_utils_read_string_from_buffer (guint8   **buffer,
                                    guint16   *buffer_size,
-                                   gboolean   length_prefix,
+                                   guint8     length_prefix_size,
                                    guint16    max_size,
                                    gchar    **out)
 {
     guint16 string_length;
     guint16 valid_string_length;
+    guint8 string_length_8;
+    guint16 string_length_16;
 
     g_assert (out != NULL);
     g_assert (buffer != NULL);
     g_assert (buffer_size != NULL);
+    g_assert (length_prefix_size == 0 ||
+              length_prefix_size == 8 ||
+              length_prefix_size == 16);
 
-    /* If no length prefix given, read the whole buffer into a string */
-    if (!length_prefix)
+    switch (length_prefix_size) {
+    case 0:
+        /* If no length prefix given, read the whole buffer into a string */
         string_length = *buffer_size;
-    else {
-        /* We assume the length prefix is always a guint8 */
-        guint8 string_length_8;
-
+        break;
+    case 8:
         qmi_utils_read_guint8_from_buffer (buffer, buffer_size, &string_length_8);
         string_length = string_length_8;
+        break;
+    case 16:
+        qmi_utils_read_guint16_from_buffer (buffer, buffer_size, &string_length_16);
+        string_length = string_length_16;
+        break;
+    default:
+        g_assert_not_reached ();
     }
 
     if (max_size > 0 && string_length > max_size)
@@ -417,23 +428,37 @@ qmi_utils_read_fixed_size_string_from_buffer (guint8   **buffer,
 void
 qmi_utils_write_string_to_buffer (guint8      **buffer,
                                   guint16      *buffer_size,
-                                  gboolean      length_prefix,
+                                  guint8        length_prefix_size,
                                   const gchar  *in)
 {
     guint16 len;
+    guint8 len_8;
+    guint16 len_16;
 
     g_assert (in != NULL);
     g_assert (buffer != NULL);
     g_assert (buffer_size != NULL);
+    g_assert (length_prefix_size == 0 ||
+              length_prefix_size == 8 ||
+              length_prefix_size == 16);
 
     len = (guint16) strlen (in);
 
-    if (length_prefix) {
-        guint8 len_8;
-
+    switch (length_prefix_size) {
+    case 0:
+        break;
+    case 8:
         g_warn_if_fail (len <= G_MAXUINT8);
         len_8 = (guint8)len;
         qmi_utils_write_guint8_to_buffer (buffer, buffer_size, &len_8);
+        break;
+    case 16:
+        g_warn_if_fail (len <= G_MAXUINT16);
+        len_16 = (guint16)len;
+        qmi_utils_write_guint16_to_buffer (buffer, buffer_size, &len_16);
+        break;
+    default:
+        g_assert_not_reached ();
     }
 
     memcpy (*buffer, in, len);
diff --git a/libqmi-glib/qmi-utils.h b/libqmi-glib/qmi-utils.h
index 6034b64..1e7671f 100644
--- a/libqmi-glib/qmi-utils.h
+++ b/libqmi-glib/qmi-utils.h
@@ -106,12 +106,12 @@ void qmi_utils_write_sized_guint_to_buffer (guint8  **buffer,
 
 void qmi_utils_read_string_from_buffer (guint8   **buffer,
                                         guint16   *buffer_size,
-                                        gboolean   length_prefix,
+                                        guint8     length_prefix_size,
                                         guint16    max_size,
                                         gchar    **out);
 void qmi_utils_write_string_to_buffer  (guint8      **buffer,
                                         guint16      *buffer_size,
-                                        gboolean      length_prefix,
+                                        guint8        length_prefix_size,
                                         const gchar  *in);
 
 void qmi_utils_read_fixed_size_string_from_buffer (guint8   **buffer,