Merge pull request #5127 from jestabro/mask-exclusive

T8488: add support for generating and applying an exclude mask to configtree

4 files changed, 204 insertions, 11 deletions

diff --git a/libvyosconfig/Makefile b/libvyosconfig/Makefile
index 8e37495b1..26563ef78 100644
--- a/libvyosconfig/Makefile
+++ b/libvyosconfig/Makefile
@@ -42,7 +42,7 @@ all: sharedlib
 PHONY: depends
 depends:
 	sudo sh -c 'eval $$(opam env --root=/opt/opam --set-root) ;\
-		opam pin add vyos1x-config https://github.com/vyos/vyos1x-config.git#52132ad2c0992bf6f17a06173384030d93a29053 -y ; \
+		opam pin add vyos1x-config https://github.com/vyos/vyos1x-config.git#e80771d973fc249ab04fd20a6bb2463698194880 -y ; \
 		opam pin add vyconf https://github.com/vyos/vyconf.git#e25b13ae3040d02326f01bf9bedd097795fb3a62 -y'
 
 sharedlib: depends $(BUILDDIR)/libvyosconfig$(EXTDLL)
diff --git a/libvyosconfig/lib/bindings.ml b/libvyosconfig/lib/bindings.ml
index 5d0478e02..0759edae2 100644
--- a/libvyosconfig/lib/bindings.ml
+++ b/libvyosconfig/lib/bindings.ml
@@ -95,6 +95,21 @@ let write_internal c_ptr file =
     with Internal.Write_error msg ->
         error_message := msg
 
+let read_internal_string s =
+    (* alert exn Internal.read_string:
+        [Internal.Read_error] caught
+     *)
+    try
+        error_message := "";
+        let ct = (I.read_string[@alert "-exn"]) s in
+        Ctypes.Root.create ct
+    with Internal.Read_error msg ->
+        error_message := msg; Ctypes.null
+
+let write_internal_string c_ptr =
+    let ct = Root.get c_ptr in
+    I.write_string ct
+
 let render_json_reference_tree c_ptr =
     RT.render_json (Root.get c_ptr)
 
@@ -462,7 +477,7 @@ let reference_tree_to_json internal_cache from_dir to_file =
             let s = Printf.sprintf "Write_error \'%s\'" msg in
             error_message := s; 1
 
-let mask_tree c_ptr_l c_ptr_r =
+let mask_tree c_ptr_l c_ptr_r exclusive =
     (* alert exn CD.mask_tree:
         [Config_diff.Incommensurable] caught
         [Config_diff.Empty_comparison] caught
@@ -470,12 +485,24 @@ let mask_tree c_ptr_l c_ptr_r =
     let ct_l = Root.get c_ptr_l in
     let ct_r = Root.get c_ptr_r in
     try
-        let ct_ret = (CD.mask_tree[@alert "-exn"]) ct_l ct_r in
+        let ct_ret = (CD.mask_tree[@alert "-exn"]) ~exclusive:exclusive ct_l ct_r in
         Ctypes.Root.create ct_ret
     with
         | CD.Incommensurable -> error_message := "Incommensurable"; Ctypes.null
         | CD.Empty_comparison -> error_message := "Empty comparison"; Ctypes.null
 
+let subtree_from_partial r_ptr c_ptr i_ptr path =
+    let rt = Root.get r_ptr in
+    let ct = Root.get c_ptr in
+    let input = Root.get i_ptr in
+    let path = split_on_whitespace path in
+    try
+        let ct_ret = (CD.subtree_from_partial[@alert "-exn"]) rt ct input path in
+        Ctypes.Root.create ct_ret
+    with
+        CD.Malformed_path s ->
+            error_message := s; Ctypes.null
+
 let validate_tree_filter c_ptr rt_cache_path validator_dir =
     (* alert exn Internal.read_internal:
         [Internal.Read_error] caught
@@ -513,6 +540,8 @@ struct
   let () = I.internal "to_commands" ((ptr void) @-> string @-> returning string) render_commands
   let () = I.internal "read_internal" (string @-> returning (ptr void)) read_internal
   let () = I.internal "write_internal" ((ptr void) @-> string @-> returning void) write_internal
+  let () = I.internal "read_internal_string" (string @-> returning (ptr void)) read_internal_string
+  let () = I.internal "write_internal_string" ((ptr void) @-> returning string) write_internal_string
   let () = I.internal "to_json_reference_tree" ((ptr void) @-> returning string) render_json_reference_tree
   let () = I.internal "read_internal_reference_tree" (string @-> returning (ptr void)) read_internal_reference_tree
   let () = I.internal "write_internal_reference_tree" ((ptr void) @-> string @-> returning void) write_internal_reference_tree
@@ -539,7 +568,8 @@ struct
   let () = I.internal "tree_union" ((ptr void) @-> (ptr void) @-> returning (ptr void)) tree_union
   let () = I.internal "tree_merge" (bool @-> (ptr void) @-> (ptr void) @-> returning (ptr void)) tree_merge
   let () = I.internal "reference_tree_to_json" (string @-> string @-> string @-> returning int) reference_tree_to_json
-  let () = I.internal "mask_tree" ((ptr void) @-> (ptr void) @-> returning (ptr void)) mask_tree
+  let () = I.internal "mask_tree" ((ptr void) @-> (ptr void) @-> bool @-> returning (ptr void)) mask_tree
+  let () = I.internal "subtree_from_partial" ((ptr void) @-> (ptr void) @-> (ptr void) @-> string @-> returning (ptr void)) subtree_from_partial
   let () = I.internal "validate_tree_filter" ((ptr void) @-> string @-> string @-> returning (ptr void)) validate_tree_filter
   let () = I.internal "config_dict" ((ptr void) @-> (ptr void) @-> (ptr void) @-> string @-> bool @-> bool @-> returning string) config_dict
 end
diff --git a/python/vyos/configtree.py b/python/vyos/configtree.py
index 61ef6428c..d92137c14 100644
--- a/python/vyos/configtree.py
+++ b/python/vyos/configtree.py
@@ -18,6 +18,12 @@ import json
 import logging
 
 from ctypes import cdll, c_char_p, c_void_p, c_int, c_bool
+from typing import TYPE_CHECKING
+
+# https://peps.python.org/pep-0484/#forward-references
+# for type 'ConfigDict'
+if TYPE_CHECKING:
+    from vyos.referencetree import ReferenceTree
 
 BUILD_PATH = '/tmp/libvyosconfig/_build/libvyosconfig.so'
 INSTALL_PATH = '/usr/lib/libvyosconfig.so.0'
@@ -67,11 +73,21 @@ class ConfigTreeError(Exception):
 
 class ConfigTree(object):
     def __init__(
-        self, config_string=None, address=None, internal=None, libpath=LIBPATH
+        self,
+        config_string=None,
+        address=None,
+        internal=None,
+        internal_string=None,
+        libpath=LIBPATH,
     ):
-        if config_string is None and address is None and internal is None:
+        if (
+            config_string is None
+            and address is None
+            and internal is None
+            and internal_string is None
+        ):
             raise TypeError(
-                "ConfigTree() requires one of 'config_string', 'address', or 'internal'"
+                "ConfigTree() requires one of 'config_string', 'address', 'internal', or 'internal_string'"
             )
 
         self.__config = None
@@ -101,6 +117,14 @@ class ConfigTree(object):
         self.__write_internal = self.__lib.write_internal
         self.__write_internal.argtypes = [c_void_p, c_char_p]
 
+        self.__read_internal_string = self.__lib.read_internal_string
+        self.__read_internal_string.argtypes = [c_char_p]
+        self.__read_internal_string.restype = c_void_p
+
+        self.__write_internal_string = self.__lib.write_internal_string
+        self.__write_internal_string.argtypes = [c_void_p]
+        self.__write_internal_string.restype = c_char_p
+
         self.__to_json = self.__lib.to_json
         self.__to_json.argtypes = [c_void_p]
         self.__to_json.restype = c_char_p
@@ -206,7 +230,19 @@ class ConfigTree(object):
             config = self.__read_internal(internal.encode())
             if config is None:
                 msg = self.__get_error().decode()
-                raise ValueError('Failed to read internal rep: {0}'.format(msg))
+                raise ValueError(
+                    f'Failed to read internal representation from file {internal}: {msg}'
+                )
+            else:
+                self.__config = config
+                self.__version = ''
+        elif internal_string is not None:
+            config = self.__read_internal_string(internal_string.encode())
+            if config is None:
+                msg = self.__get_error().decode()
+                raise ValueError(
+                    f'Failed to read internal representation from string: {msg}'
+                )
             else:
                 self.__config = config
                 self.__version = ''
@@ -216,7 +252,7 @@ class ConfigTree(object):
             config = self.__from_string(config_section.encode())
             if config is None:
                 msg = self.__get_error().decode()
-                raise ValueError('Failed to parse config: {0}'.format(msg))
+                raise ValueError(f'Failed to parse config: {msg}')
             else:
                 self.__config = config
                 self.__version = version_section
@@ -250,6 +286,10 @@ class ConfigTree(object):
     def write_cache(self, file_name):
         self.__write_internal(self.get_tree(), file_name.encode())
 
+    def write_internal_string(self) -> str:
+        res = self.__write_internal_string(self.get_tree())
+        return res.decode()
+
     def to_string(self, ordered_values=False, no_version=False):
         config_string = self.__to_string(self.__config, ordered_values).decode()
         config_string = unescape_backslash(config_string)
@@ -584,13 +624,80 @@ def mask_inclusive(left, right, libpath=LIBPATH):
     try:
         __lib = cdll.LoadLibrary(libpath)
         __mask_tree = __lib.mask_tree
-        __mask_tree.argtypes = [c_void_p, c_void_p]
+        __mask_tree.argtypes = [c_void_p, c_void_p, c_bool]
+        __mask_tree.restype = c_void_p
+        __get_error = __lib.get_error
+        __get_error.argtypes = []
+        __get_error.restype = c_char_p
+
+        res = __mask_tree(left.get_tree(), right.get_tree(), False)
+    except Exception as e:
+        raise ConfigTreeError(e)
+    if not res:
+        msg = __get_error().decode()
+        raise ConfigTreeError(msg)
+
+    tree = ConfigTree(address=res)
+
+    return tree
+
+
+def mask_exclusive(left, right, libpath=LIBPATH):
+    if not (isinstance(left, ConfigTree) and isinstance(right, ConfigTree)):
+        raise TypeError('Arguments must be instances of ConfigTree')
+
+    try:
+        __lib = cdll.LoadLibrary(libpath)
+        __mask_tree = __lib.mask_tree
+        __mask_tree.argtypes = [c_void_p, c_void_p, c_bool]
         __mask_tree.restype = c_void_p
         __get_error = __lib.get_error
         __get_error.argtypes = []
         __get_error.restype = c_char_p
 
-        res = __mask_tree(left.get_tree(), right.get_tree())
+        res = __mask_tree(left.get_tree(), right.get_tree(), True)
+    except Exception as e:
+        raise ConfigTreeError(e)
+    if not res:
+        msg = __get_error().decode()
+        raise ConfigTreeError(msg)
+
+    tree = ConfigTree(address=res)
+
+    return tree
+
+
+def subtree_from_partial(
+    config_tree: ConfigTree,
+    path: list[str],
+    reference_tree: 'ReferenceTree',
+    start: ConfigTree = None,
+    libpath=LIBPATH,
+):
+    if start:
+        if not isinstance(start, ConfigTree):
+            raise TypeError("Argument 'start' must be an instance of ConfigTree")
+    else:
+        start = ConfigTree('')
+
+    check_path(path)
+    path_str = ' '.join(map(str, path)).encode()
+
+    try:
+        __lib = cdll.LoadLibrary(libpath)
+        __subtree_from_partial = __lib.subtree_from_partial
+        __subtree_from_partial.argtypes = [c_void_p, c_void_p, c_void_p, c_char_p]
+        __subtree_from_partial.restype = c_void_p
+        __get_error = __lib.get_error
+        __get_error.argtypes = []
+        __get_error.restype = c_char_p
+
+        res = __subtree_from_partial(
+            reference_tree.get_tree(),
+            config_tree.get_tree(),
+            start.get_tree(),
+            path_str,
+        )
     except Exception as e:
         raise ConfigTreeError(e)
     if not res:
diff --git a/python/vyos/derivedtree.py b/python/vyos/derivedtree.py
new file mode 100644
index 000000000..0a57921b2
--- /dev/null
+++ b/python/vyos/derivedtree.py
@@ -0,0 +1,56 @@
+# Copyright (C) VyOS Inc.
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this library.  If not, see <http://www.gnu.org/licenses/>.
+
+
+from vyos.referencetree import ReferenceTree
+from vyos.configtree import ConfigTree
+from vyos.configtree import ConfigTreeError
+from vyos.configtree import subtree_from_partial
+
+
+class DerivedTreeError(Exception):
+    """Error to be raised by functions of derivedtree"""
+
+
+def subtree_from_list_of_partial_paths(
+    ctree: ConfigTree, paths: list[list[str]], accumulator: ConfigTree = None
+):
+    """Return the union of subtrees of the ConfigTree argument matching each
+    of the 'partial' paths. A partial path is one that may or may not
+    contain intervening tag node values, in which case it will match for all
+    values that apply.
+
+    An existing subtree may be passed as the initial value of accumulator.
+    """
+    if accumulator:
+        if not isinstance(accumulator, ConfigTree):
+            raise TypeError("Argument 'accumulator' must be an instance of ConfigTree")
+    else:
+        accumulator = ConfigTree('')
+
+    rtree = ReferenceTree()
+
+    errors = []
+    for path in paths:
+        try:
+            accumulator = subtree_from_partial(ctree, path, rtree, accumulator)
+        except ConfigTreeError as e:
+            errors.append(str(e))
+            continue
+
+    if errors:
+        raise DerivedTreeError(f'Nonsensical paths: {errors}')
+
+    return accumulator