dissector: Handle pointers

Read the pointer and if not 0 create a function to parse it and
call it.

Signed-off-by: Frediano Ziglio <fziglio@redhat.com>

1 files changed, 49 insertions, 0 deletions

diff --git a/python_modules/dissector.py b/python_modules/dissector.py
index 0456ab8..db5d364 100644
--- a/python_modules/dissector.py
+++ b/python_modules/dissector.py
@@ -358,9 +358,58 @@ def write_array(writer, container, member, nelements, array, dest, scope):
             assert(element_type.is_struct())
             write_struct(writer, member, element_type, index, dest, scope)
 
+
+def write_ptr_function(writer, target_type, container, member, dest, scope):
+    nelements = ''
+    if target_type.is_array():
+        parse_function = "parse_array_%s" % target_type.element_type.primitive_type()
+        nelements = ', guint32 nelements'
+    else:
+        parse_function = "parse_struct_%s" % target_type.c_type()
+    if writer.is_generated("parser", parse_function):
+        return '%s(glb, %s, offset)' % (parse_function, dest.level.tree)
+
+    writer.set_is_generated("parser", parse_function)
+
+    writer = writer.function_helper()
+    scope = writer.function(parse_function, "guint32", "GlobalInfo *glb _U_, proto_tree *tree _U_%s, guint32 offset" % nelements, True)
+
+    writer.newline()
+
+    dest = RootDestination(scope)
+    dest.is_helper = True
+    if target_type.is_array():
+        write_array(writer, None, None, "nelements", target_type, dest, scope)
+    else:
+        write_container_parser(writer, target_type, dest)
+
+    writer.statement("return offset")
+
+    writer.end_block()
+
+    return '%s(glb, %s, offset)' % (parse_function, dest.level.tree)
+
+def read_ptr(writer, t):
+    writer.assign('ptr', '%s(glb->tvb, offset)' % primitive_read_func(t))
+    writer.increment('offset', str(t.get_fixed_nw_size()))
+
 def write_pointer(writer, container, member, t, dest, scope):
     assert(t.is_pointer())
 
+    if not scope.variable_defined('ptr'):
+        scope.variable_def('guint32', 'ptr')
+    read_ptr(writer, t)
+    with writer.if_block('ptr'):
+        writer.variable_def('guint32', 'save_offset = offset')
+        writer.assign('offset', 'ptr + glb->message_offset')
+        if t.target_type.is_array():
+            nelements = read_array_len(writer, member.name, t.target_type, dest, scope, True)
+            write_array(writer, container, member, nelements, t.target_type, dest, scope)
+        else:
+            stmt = write_ptr_function(writer, t.target_type, container, member, dest, scope)
+            writer.statement(stmt)
+        writer.assign('offset', 'save_offset')
+
 
 def write_struct_func(writer, t, func_name, index):
     func_name = 'dissect_spice_struct_' + t.name