userspace: net sockets are kernel objects

Any data structure declaration tagged with __net_socket will end up
in the kernel object table with type K_OBJ_NET_SOCKET. These all
correspond to objects which are associated with socket file
descriptors and can handle the socket vtable API.

Signed-off-by: Andrew Boie <[email protected]>

Author: Andrew Boie

include/toolchain/common.h

@@ -132,11 +132,17 @@
 #define __syscall
 #endif /* #ifndef ZTEST_UNITTEST */
 
-/* Used as a sentinel by parse_syscalls.py to identify what API structs
- * define driver subsystems.
+/* Definitions for struct declaration tags. These are sentinel values used by
+ * parse_syscalls.py to gather a list of names of struct declarations that
+ * have these tags applied for them.
  */
+
+/* Indicates this is a driver subsystem */
 #define __subsystem
 
+/* Indicates this is a network socket object */
+#define __net_socket
+
 #ifndef BUILD_ASSERT
 /* Compile-time assertion that makes the build to fail.
  * Common implementation swallows the message.

scripts/gen_kobject_list.py

@@ -80,6 +80,10 @@
 #
 #  - The third items is a boolean indicating whether this item can be
 #    dynamically allocated with k_object_alloc()
+#
+# Key names in all caps do not correspond to a specific data type but instead
+# indicate that objects of its type are of a family of compatible data
+# structures
 
 # Regular dictionaries are ordered only with Python 3.6 and
 # above. Good summary and pointers to official documents at:
@@ -97,6 +101,7 @@
     ("k_timer", (None, False, True)),
     ("z_thread_stack_element", (None, False, False)),
     ("device", (None, False, False)),
+    ("NET_SOCKET", (None, False, False)),
     ("sys_mutex", (None, True, False)),
     ("k_futex", (None, True, False))
 ])
@@ -118,6 +123,9 @@ def kobject_to_enum(kobj):
     #};
 ]
 
+# Names of all structs tagged with __net_socket, found by parse_syscalls.py
+net_sockets = [ ]
+
 def subsystem_to_enum(subsys):
     return "K_OBJ_DRIVER_" + subsys[:-11].upper()
 
@@ -402,6 +410,8 @@ def analyze_die_struct(die):
         type_env[offset] = KobjectType(offset, name, size)
     elif name in subsystems:
         type_env[offset] = KobjectType(offset, name, size, api=True)
+    elif name in net_sockets:
+        type_env[offset] = KobjectType(offset, "NET_SOCKET", size)
     else:
         at = AggregateType(offset, name, size)
         type_env[offset] = at
@@ -919,6 +929,7 @@ def parse_subsystems_list_file(path):
     with open(path, "r") as fp:
         subsys_list = json.load(fp)
     subsystems.extend(subsys_list["__subsystem"])
+    net_sockets.extend(subsys_list["__net_socket"])
 
 def parse_args():
     global args

scripts/parse_syscalls.py

@@ -40,7 +40,7 @@
 [)]                             # Closing parenthesis
 ''', regex_flags)
 
-struct_tags = ["__subsystem"]
+struct_tags = ["__subsystem", "__net_socket"]
 
 tagged_struct_decl_template = r'''
 %s\s+                           # tag, must be first