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1 | // SPDX-License-Identifier: GPL-2.0-or-later | |
2 | /* | |
3 | * clippy (CLI preparator in python) wrapper for FRR command_graph | |
4 | * Copyright (C) 2016-2017 David Lamparter for NetDEF, Inc. | |
5 | */ | |
6 | ||
7 | /* note: this wrapper is intended to be used as build-time helper. while | |
8 | * it should be generally correct and proper, there may be the occasional | |
9 | * memory leak or SEGV for things that haven't been well-tested. | |
10 | */ | |
11 | ||
12 | /* This file is "exempt" from having | |
13 | #include "config.h" | |
14 | * as the first include statement because Python.h also does environment | |
15 | * setup & these trample over each other. | |
16 | */ | |
17 | ||
18 | #ifdef HAVE_CONFIG_H | |
19 | #include "config.h" | |
20 | #endif | |
21 | #include <Python.h> | |
22 | #include "structmember.h" | |
23 | #include <string.h> | |
24 | #include <stdlib.h> | |
25 | ||
26 | #include "command_graph.h" | |
27 | #include "clippy.h" | |
28 | ||
29 | struct wrap_graph; | |
30 | static PyObject *graph_to_pyobj(struct wrap_graph *graph, | |
31 | struct graph_node *gn); | |
32 | ||
33 | /* | |
34 | * nodes are wrapped as follows: | |
35 | * - instances can only be acquired from a graph | |
36 | * - the same node will return the same wrapper object (they're buffered | |
37 | * through "idx") | |
38 | * - a reference is held onto the graph | |
39 | * - fields are copied for easy access with PyMemberDef | |
40 | */ | |
41 | struct wrap_graph_node { | |
42 | PyObject_HEAD | |
43 | ||
44 | bool allowrepeat; | |
45 | const char *type; | |
46 | ||
47 | bool deprecated; | |
48 | bool hidden; | |
49 | const char *text; | |
50 | const char *desc; | |
51 | const char *varname; | |
52 | long long min, max; | |
53 | ||
54 | struct graph_node *node; | |
55 | struct wrap_graph *wgraph; | |
56 | size_t idx; | |
57 | }; | |
58 | ||
59 | /* | |
60 | * graphs are wrapped as follows: | |
61 | * - they can only be created by parsing a definition string | |
62 | * - there's a table here for the wrapped nodes (nodewrappers), indexed | |
63 | * by "idx" (corresponds to node's position in graph's table of nodes) | |
64 | * - graphs do NOT hold references to nodes (would be circular) | |
65 | */ | |
66 | struct wrap_graph { | |
67 | PyObject_HEAD | |
68 | ||
69 | char *definition; | |
70 | struct graph *graph; | |
71 | struct wrap_graph_node **nodewrappers; | |
72 | }; | |
73 | ||
74 | static PyObject *refuse_new(PyTypeObject *type, PyObject *args, PyObject *kwds) | |
75 | { | |
76 | PyErr_SetString(PyExc_ValueError, | |
77 | "cannot create instances of this type"); | |
78 | return NULL; | |
79 | } | |
80 | ||
81 | #define member(name, type) \ | |
82 | { \ | |
83 | (char *)#name, type, offsetof(struct wrap_graph_node, name), \ | |
84 | READONLY, (char *)#name " (" #type ")" \ | |
85 | } | |
86 | static PyMemberDef members_graph_node[] = { | |
87 | member(allowrepeat, T_BOOL), member(type, T_STRING), | |
88 | member(deprecated, T_BOOL), member(hidden, T_BOOL), | |
89 | member(text, T_STRING), member(desc, T_STRING), | |
90 | member(min, T_LONGLONG), member(max, T_LONGLONG), | |
91 | member(varname, T_STRING), {}, | |
92 | }; | |
93 | #undef member | |
94 | ||
95 | /* | |
96 | * node.next() -- returns list of all "next" nodes. | |
97 | * this will include circles if the graph has them. | |
98 | */ | |
99 | static PyObject *graph_node_next(PyObject *self, PyObject *args) | |
100 | { | |
101 | struct wrap_graph_node *wrap = (struct wrap_graph_node *)self; | |
102 | PyObject *pylist; | |
103 | ||
104 | if (wrap->node->data | |
105 | && ((struct cmd_token *)wrap->node->data)->type == END_TKN) | |
106 | return PyList_New(0); | |
107 | pylist = PyList_New(vector_active(wrap->node->to)); | |
108 | for (size_t i = 0; i < vector_active(wrap->node->to); i++) { | |
109 | struct graph_node *gn = vector_slot(wrap->node->to, i); | |
110 | PyList_SetItem(pylist, i, graph_to_pyobj(wrap->wgraph, gn)); | |
111 | } | |
112 | return pylist; | |
113 | }; | |
114 | ||
115 | /* | |
116 | * node.join() -- return FORK's JOIN node or None | |
117 | */ | |
118 | static PyObject *graph_node_join(PyObject *self, PyObject *args) | |
119 | { | |
120 | struct wrap_graph_node *wrap = (struct wrap_graph_node *)self; | |
121 | ||
122 | if (!wrap->node->data | |
123 | || ((struct cmd_token *)wrap->node->data)->type == END_TKN) | |
124 | Py_RETURN_NONE; | |
125 | ||
126 | struct cmd_token *tok = wrap->node->data; | |
127 | if (tok->type != FORK_TKN) | |
128 | Py_RETURN_NONE; | |
129 | ||
130 | return graph_to_pyobj(wrap->wgraph, tok->forkjoin); | |
131 | }; | |
132 | ||
133 | static PyMethodDef methods_graph_node[] = { | |
134 | {"next", graph_node_next, METH_NOARGS, "outbound graph edge list"}, | |
135 | {"join", graph_node_join, METH_NOARGS, "outbound join node"}, | |
136 | {}}; | |
137 | ||
138 | static void graph_node_wrap_free(void *arg) | |
139 | { | |
140 | struct wrap_graph_node *wrap = arg; | |
141 | wrap->wgraph->nodewrappers[wrap->idx] = NULL; | |
142 | Py_DECREF(wrap->wgraph); | |
143 | } | |
144 | ||
145 | static PyTypeObject typeobj_graph_node = { | |
146 | PyVarObject_HEAD_INIT(NULL, 0).tp_name = "_clippy.GraphNode", | |
147 | .tp_basicsize = sizeof(struct wrap_graph_node), | |
148 | .tp_flags = Py_TPFLAGS_DEFAULT, | |
149 | .tp_doc = "struct graph_node *", | |
150 | .tp_new = refuse_new, | |
151 | .tp_free = graph_node_wrap_free, | |
152 | .tp_members = members_graph_node, | |
153 | .tp_methods = methods_graph_node, | |
154 | }; | |
155 | ||
156 | static PyObject *graph_to_pyobj(struct wrap_graph *wgraph, | |
157 | struct graph_node *gn) | |
158 | { | |
159 | struct wrap_graph_node *wrap; | |
160 | size_t i; | |
161 | ||
162 | for (i = 0; i < vector_active(wgraph->graph->nodes); i++) | |
163 | if (vector_slot(wgraph->graph->nodes, i) == gn) | |
164 | break; | |
165 | if (i == vector_active(wgraph->graph->nodes)) { | |
166 | PyErr_SetString(PyExc_ValueError, "cannot find node in graph"); | |
167 | return NULL; | |
168 | } | |
169 | if (wgraph->nodewrappers[i]) { | |
170 | PyObject *obj = (PyObject *)wgraph->nodewrappers[i]; | |
171 | Py_INCREF(obj); | |
172 | return obj; | |
173 | } | |
174 | ||
175 | wrap = (struct wrap_graph_node *)typeobj_graph_node.tp_alloc( | |
176 | &typeobj_graph_node, 0); | |
177 | if (!wrap) | |
178 | return NULL; | |
179 | wgraph->nodewrappers[i] = wrap; | |
180 | Py_INCREF(wgraph); | |
181 | ||
182 | wrap->idx = i; | |
183 | wrap->wgraph = wgraph; | |
184 | wrap->node = gn; | |
185 | wrap->type = "NULL"; | |
186 | wrap->allowrepeat = false; | |
187 | if (gn->data) { | |
188 | struct cmd_token *tok = gn->data; | |
189 | switch (tok->type) { | |
190 | #define item(x) \ | |
191 | case x: \ | |
192 | wrap->type = #x; \ | |
193 | break /* no semicolon */ | |
194 | ||
195 | item(WORD_TKN); // words | |
196 | item(VARIABLE_TKN); // almost anything | |
197 | item(RANGE_TKN); // integer range | |
198 | item(IPV4_TKN); // IPV4 addresses | |
199 | item(IPV4_PREFIX_TKN); // IPV4 network prefixes | |
200 | item(IPV6_TKN); // IPV6 prefixes | |
201 | item(IPV6_PREFIX_TKN); // IPV6 network prefixes | |
202 | item(MAC_TKN); // MAC address | |
203 | item(MAC_PREFIX_TKN); // MAC address with mask | |
204 | item(ASNUM_TKN); // ASNUM | |
205 | ||
206 | /* plumbing types */ | |
207 | item(FORK_TKN); | |
208 | item(JOIN_TKN); | |
209 | item(START_TKN); | |
210 | item(END_TKN); | |
211 | item(NEG_ONLY_TKN); | |
212 | #undef item | |
213 | default: | |
214 | wrap->type = "???"; | |
215 | } | |
216 | ||
217 | wrap->deprecated = !!(tok->attr & CMD_ATTR_DEPRECATED); | |
218 | wrap->hidden = !!(tok->attr & CMD_ATTR_HIDDEN); | |
219 | wrap->text = tok->text; | |
220 | wrap->desc = tok->desc; | |
221 | wrap->varname = tok->varname; | |
222 | wrap->min = tok->min; | |
223 | wrap->max = tok->max; | |
224 | wrap->allowrepeat = tok->allowrepeat; | |
225 | } | |
226 | ||
227 | return (PyObject *)wrap; | |
228 | } | |
229 | ||
230 | #define member(name, type) \ | |
231 | { \ | |
232 | (char *)#name, type, offsetof(struct wrap_graph, name), \ | |
233 | READONLY, (char *)#name " (" #type ")" \ | |
234 | } | |
235 | static PyMemberDef members_graph[] = { | |
236 | member(definition, T_STRING), | |
237 | {}, | |
238 | }; | |
239 | #undef member | |
240 | ||
241 | /* graph.first() - root node */ | |
242 | static PyObject *graph_first(PyObject *self, PyObject *args) | |
243 | { | |
244 | struct wrap_graph *gwrap = (struct wrap_graph *)self; | |
245 | struct graph_node *gn = vector_slot(gwrap->graph->nodes, 0); | |
246 | return graph_to_pyobj(gwrap, gn); | |
247 | }; | |
248 | ||
249 | static PyMethodDef methods_graph[] = { | |
250 | {"first", graph_first, METH_NOARGS, "first graph node"}, | |
251 | {}}; | |
252 | ||
253 | static PyObject *graph_parse(PyTypeObject *type, PyObject *args, | |
254 | PyObject *kwds); | |
255 | ||
256 | static void graph_wrap_free(void *arg) | |
257 | { | |
258 | struct wrap_graph *wgraph = arg; | |
259 | ||
260 | graph_delete_graph(wgraph->graph); | |
261 | free(wgraph->nodewrappers); | |
262 | free(wgraph->definition); | |
263 | } | |
264 | ||
265 | static PyTypeObject typeobj_graph = { | |
266 | PyVarObject_HEAD_INIT(NULL, 0).tp_name = "_clippy.Graph", | |
267 | .tp_basicsize = sizeof(struct wrap_graph), | |
268 | .tp_flags = Py_TPFLAGS_DEFAULT, | |
269 | .tp_doc = "struct graph *", | |
270 | .tp_new = graph_parse, | |
271 | .tp_free = graph_wrap_free, | |
272 | .tp_members = members_graph, | |
273 | .tp_methods = methods_graph, | |
274 | }; | |
275 | ||
276 | /* top call / entrypoint for python code */ | |
277 | static PyObject *graph_parse(PyTypeObject *type, PyObject *args, PyObject *kwds) | |
278 | { | |
279 | const char *def, *doc = NULL; | |
280 | struct wrap_graph *gwrap; | |
281 | static const char *kwnames[] = {"cmddef", "doc", NULL}; | |
282 | ||
283 | gwrap = (struct wrap_graph *)typeobj_graph.tp_alloc(&typeobj_graph, 0); | |
284 | if (!gwrap) | |
285 | return NULL; | |
286 | ||
287 | if (!PyArg_ParseTupleAndKeywords(args, kwds, "s|s", (char **)kwnames, | |
288 | &def, &doc)) | |
289 | return NULL; | |
290 | ||
291 | struct graph *graph = graph_new(); | |
292 | struct cmd_token *token = cmd_token_new(START_TKN, 0, NULL, NULL); | |
293 | graph_new_node(graph, token, (void (*)(void *)) & cmd_token_del); | |
294 | ||
295 | struct cmd_element cmd = {.string = def, .doc = doc}; | |
296 | cmd_graph_parse(graph, &cmd); | |
297 | cmd_graph_names(graph); | |
298 | ||
299 | gwrap->graph = graph; | |
300 | gwrap->definition = strdup(def); | |
301 | gwrap->nodewrappers = calloc(vector_active(graph->nodes), | |
302 | sizeof(gwrap->nodewrappers[0])); | |
303 | return (PyObject *)gwrap; | |
304 | } | |
305 | ||
306 | static PyMethodDef clippy_methods[] = { | |
307 | {"parse", clippy_parse, METH_VARARGS, "Parse a C file"}, | |
308 | {NULL, NULL, 0, NULL}}; | |
309 | ||
310 | #if PY_MAJOR_VERSION >= 3 | |
311 | static struct PyModuleDef pymoddef_clippy = { | |
312 | PyModuleDef_HEAD_INIT, | |
313 | "_clippy", | |
314 | NULL, /* docstring */ | |
315 | -1, | |
316 | clippy_methods, | |
317 | }; | |
318 | #define modcreate() PyModule_Create(&pymoddef_clippy) | |
319 | #define initret(val) return val; | |
320 | #else | |
321 | #define modcreate() Py_InitModule("_clippy", clippy_methods) | |
322 | #define initret(val) \ | |
323 | do { \ | |
324 | if (!val) \ | |
325 | Py_FatalError("initialization failure"); \ | |
326 | return; \ | |
327 | } while (0) | |
328 | #endif | |
329 | ||
330 | #pragma GCC diagnostic ignored "-Wstrict-aliasing" | |
331 | PyMODINIT_FUNC command_py_init(void) | |
332 | { | |
333 | PyObject *pymod; | |
334 | ||
335 | if (PyType_Ready(&typeobj_graph_node) < 0) | |
336 | initret(NULL); | |
337 | if (PyType_Ready(&typeobj_graph) < 0) | |
338 | initret(NULL); | |
339 | ||
340 | pymod = modcreate(); | |
341 | if (!pymod) | |
342 | initret(NULL); | |
343 | ||
344 | if (PyModule_AddIntMacro(pymod, CMD_ATTR_YANG) | |
345 | || PyModule_AddIntMacro(pymod, CMD_ATTR_HIDDEN) | |
346 | || PyModule_AddIntMacro(pymod, CMD_ATTR_DEPRECATED) | |
347 | || PyModule_AddIntMacro(pymod, CMD_ATTR_NOSH)) | |
348 | initret(NULL); | |
349 | ||
350 | Py_INCREF(&typeobj_graph_node); | |
351 | PyModule_AddObject(pymod, "GraphNode", (PyObject *)&typeobj_graph_node); | |
352 | Py_INCREF(&typeobj_graph); | |
353 | PyModule_AddObject(pymod, "Graph", (PyObject *)&typeobj_graph); | |
354 | if (!elf_py_init(pymod)) | |
355 | initret(NULL); | |
356 | initret(pymod); | |
357 | } |