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1 | /* | |
2 | * clippy (CLI preparator in python) wrapper for FRR command_graph | |
3 | * Copyright (C) 2016-2017 David Lamparter for NetDEF, Inc. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms of the GNU General Public License as published by the Free | |
7 | * Software Foundation; either version 2 of the License, or (at your option) | |
8 | * any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
11 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
12 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
13 | * more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License along | |
16 | * with this program; see the file COPYING; if not, write to the Free Software | |
17 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
18 | */ | |
19 | ||
20 | /* note: this wrapper is intended to be used as build-time helper. while | |
21 | * it should be generally correct and proper, there may be the occasional | |
22 | * memory leak or SEGV for things that haven't been well-tested. | |
23 | */ | |
24 | ||
25 | #include <Python.h> | |
26 | #include "structmember.h" | |
27 | #include <string.h> | |
28 | #include <stdlib.h> | |
29 | ||
30 | #include "command_graph.h" | |
31 | #include "clippy.h" | |
32 | ||
33 | struct wrap_graph; | |
34 | static PyObject *graph_to_pyobj(struct wrap_graph *graph, | |
35 | struct graph_node *gn); | |
36 | ||
37 | /* | |
38 | * nodes are wrapped as follows: | |
39 | * - instances can only be acquired from a graph | |
40 | * - the same node will return the same wrapper object (they're buffered | |
41 | * through "idx") | |
42 | * - a reference is held onto the graph | |
43 | * - fields are copied for easy access with PyMemberDef | |
44 | */ | |
45 | struct wrap_graph_node { | |
46 | PyObject_HEAD | |
47 | ||
48 | bool allowrepeat; | |
49 | const char *type; | |
50 | ||
51 | bool deprecated; | |
52 | bool hidden; | |
53 | const char *text; | |
54 | const char *desc; | |
55 | const char *varname; | |
56 | long long min, max; | |
57 | ||
58 | struct graph_node *node; | |
59 | struct wrap_graph *wgraph; | |
60 | size_t idx; | |
61 | }; | |
62 | ||
63 | /* | |
64 | * graphs are wrapped as follows: | |
65 | * - they can only be created by parsing a definition string | |
66 | * - there's a table here for the wrapped nodes (nodewrappers), indexed | |
67 | * by "idx" (corresponds to node's position in graph's table of nodes) | |
68 | * - graphs do NOT hold references to nodes (would be circular) | |
69 | */ | |
70 | struct wrap_graph { | |
71 | PyObject_HEAD | |
72 | ||
73 | char *definition; | |
74 | struct graph *graph; | |
75 | struct wrap_graph_node **nodewrappers; | |
76 | }; | |
77 | ||
78 | static PyObject *refuse_new(PyTypeObject *type, PyObject *args, PyObject *kwds) | |
79 | { | |
80 | PyErr_SetString(PyExc_ValueError, | |
81 | "cannot create instances of this type"); | |
82 | return NULL; | |
83 | } | |
84 | ||
85 | #define member(name, type) \ | |
86 | { \ | |
87 | (char *)#name, type, offsetof(struct wrap_graph_node, name), \ | |
88 | READONLY, (char *)#name " (" #type ")" \ | |
89 | } | |
90 | static PyMemberDef members_graph_node[] = { | |
91 | member(allowrepeat, T_BOOL), member(type, T_STRING), | |
92 | member(deprecated, T_BOOL), member(hidden, T_BOOL), | |
93 | member(text, T_STRING), member(desc, T_STRING), | |
94 | member(min, T_LONGLONG), member(max, T_LONGLONG), | |
95 | member(varname, T_STRING), {}, | |
96 | }; | |
97 | #undef member | |
98 | ||
99 | /* | |
100 | * node.next() -- returns list of all "next" nodes. | |
101 | * this will include circles if the graph has them. | |
102 | */ | |
103 | static PyObject *graph_node_next(PyObject *self, PyObject *args) | |
104 | { | |
105 | struct wrap_graph_node *wrap = (struct wrap_graph_node *)self; | |
106 | PyObject *pylist; | |
107 | ||
108 | if (wrap->node->data | |
109 | && ((struct cmd_token *)wrap->node->data)->type == END_TKN) | |
110 | return PyList_New(0); | |
111 | pylist = PyList_New(vector_active(wrap->node->to)); | |
112 | for (size_t i = 0; i < vector_active(wrap->node->to); i++) { | |
113 | struct graph_node *gn = vector_slot(wrap->node->to, i); | |
114 | PyList_SetItem(pylist, i, graph_to_pyobj(wrap->wgraph, gn)); | |
115 | } | |
116 | return pylist; | |
117 | }; | |
118 | ||
119 | /* | |
120 | * node.join() -- return FORK's JOIN node or None | |
121 | */ | |
122 | static PyObject *graph_node_join(PyObject *self, PyObject *args) | |
123 | { | |
124 | struct wrap_graph_node *wrap = (struct wrap_graph_node *)self; | |
125 | ||
126 | if (!wrap->node->data | |
127 | || ((struct cmd_token *)wrap->node->data)->type == END_TKN) | |
128 | Py_RETURN_NONE; | |
129 | ||
130 | struct cmd_token *tok = wrap->node->data; | |
131 | if (tok->type != FORK_TKN) | |
132 | Py_RETURN_NONE; | |
133 | ||
134 | return graph_to_pyobj(wrap->wgraph, tok->forkjoin); | |
135 | }; | |
136 | ||
137 | static PyMethodDef methods_graph_node[] = { | |
138 | {"next", graph_node_next, METH_NOARGS, "outbound graph edge list"}, | |
139 | {"join", graph_node_join, METH_NOARGS, "outbound join node"}, | |
140 | {}}; | |
141 | ||
142 | static void graph_node_wrap_free(void *arg) | |
143 | { | |
144 | struct wrap_graph_node *wrap = arg; | |
145 | wrap->wgraph->nodewrappers[wrap->idx] = NULL; | |
146 | Py_DECREF(wrap->wgraph); | |
147 | } | |
148 | ||
149 | static PyTypeObject typeobj_graph_node = { | |
150 | PyVarObject_HEAD_INIT(NULL, 0).tp_name = "_clippy.GraphNode", | |
151 | .tp_basicsize = sizeof(struct wrap_graph_node), | |
152 | .tp_flags = Py_TPFLAGS_DEFAULT, | |
153 | .tp_doc = "struct graph_node *", | |
154 | .tp_new = refuse_new, | |
155 | .tp_free = graph_node_wrap_free, | |
156 | .tp_members = members_graph_node, | |
157 | .tp_methods = methods_graph_node, | |
158 | }; | |
159 | ||
160 | static PyObject *graph_to_pyobj(struct wrap_graph *wgraph, | |
161 | struct graph_node *gn) | |
162 | { | |
163 | struct wrap_graph_node *wrap; | |
164 | size_t i; | |
165 | ||
166 | for (i = 0; i < vector_active(wgraph->graph->nodes); i++) | |
167 | if (vector_slot(wgraph->graph->nodes, i) == gn) | |
168 | break; | |
169 | if (i == vector_active(wgraph->graph->nodes)) { | |
170 | PyErr_SetString(PyExc_ValueError, "cannot find node in graph"); | |
171 | return NULL; | |
172 | } | |
173 | if (wgraph->nodewrappers[i]) { | |
174 | PyObject *obj = (PyObject *)wgraph->nodewrappers[i]; | |
175 | Py_INCREF(obj); | |
176 | return obj; | |
177 | } | |
178 | ||
179 | wrap = (struct wrap_graph_node *)typeobj_graph_node.tp_alloc( | |
180 | &typeobj_graph_node, 0); | |
181 | if (!wrap) | |
182 | return NULL; | |
183 | wgraph->nodewrappers[i] = wrap; | |
184 | Py_INCREF(wgraph); | |
185 | ||
186 | wrap->idx = i; | |
187 | wrap->wgraph = wgraph; | |
188 | wrap->node = gn; | |
189 | wrap->type = "NULL"; | |
190 | wrap->allowrepeat = false; | |
191 | if (gn->data) { | |
192 | struct cmd_token *tok = gn->data; | |
193 | switch (tok->type) { | |
194 | #define item(x) case x: wrap->type = #x; break; | |
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 | ||
205 | /* plumbing types */ | |
206 | item(FORK_TKN) item(JOIN_TKN) item(START_TKN) | |
207 | item(END_TKN) default | |
208 | : wrap->type = "???"; | |
209 | } | |
210 | ||
211 | wrap->deprecated = (tok->attr == CMD_ATTR_DEPRECATED); | |
212 | wrap->hidden = (tok->attr == CMD_ATTR_HIDDEN); | |
213 | wrap->text = tok->text; | |
214 | wrap->desc = tok->desc; | |
215 | wrap->varname = tok->varname; | |
216 | wrap->min = tok->min; | |
217 | wrap->max = tok->max; | |
218 | wrap->allowrepeat = tok->allowrepeat; | |
219 | } | |
220 | ||
221 | return (PyObject *)wrap; | |
222 | } | |
223 | ||
224 | #define member(name, type) \ | |
225 | { \ | |
226 | (char *)#name, type, offsetof(struct wrap_graph, name), \ | |
227 | READONLY, (char *)#name " (" #type ")" \ | |
228 | } | |
229 | static PyMemberDef members_graph[] = { | |
230 | member(definition, T_STRING), | |
231 | {}, | |
232 | }; | |
233 | #undef member | |
234 | ||
235 | /* graph.first() - root node */ | |
236 | static PyObject *graph_first(PyObject *self, PyObject *args) | |
237 | { | |
238 | struct wrap_graph *gwrap = (struct wrap_graph *)self; | |
239 | struct graph_node *gn = vector_slot(gwrap->graph->nodes, 0); | |
240 | return graph_to_pyobj(gwrap, gn); | |
241 | }; | |
242 | ||
243 | static PyMethodDef methods_graph[] = { | |
244 | {"first", graph_first, METH_NOARGS, "first graph node"}, | |
245 | {}}; | |
246 | ||
247 | static PyObject *graph_parse(PyTypeObject *type, PyObject *args, | |
248 | PyObject *kwds); | |
249 | ||
250 | static void graph_wrap_free(void *arg) | |
251 | { | |
252 | struct wrap_graph *wgraph = arg; | |
253 | ||
254 | graph_delete_graph(wgraph->graph); | |
255 | free(wgraph->nodewrappers); | |
256 | free(wgraph->definition); | |
257 | } | |
258 | ||
259 | static PyTypeObject typeobj_graph = { | |
260 | PyVarObject_HEAD_INIT(NULL, 0).tp_name = "_clippy.Graph", | |
261 | .tp_basicsize = sizeof(struct wrap_graph), | |
262 | .tp_flags = Py_TPFLAGS_DEFAULT, | |
263 | .tp_doc = "struct graph *", | |
264 | .tp_new = graph_parse, | |
265 | .tp_free = graph_wrap_free, | |
266 | .tp_members = members_graph, | |
267 | .tp_methods = methods_graph, | |
268 | }; | |
269 | ||
270 | /* top call / entrypoint for python code */ | |
271 | static PyObject *graph_parse(PyTypeObject *type, PyObject *args, PyObject *kwds) | |
272 | { | |
273 | const char *def, *doc = NULL; | |
274 | struct wrap_graph *gwrap; | |
275 | static const char *kwnames[] = {"cmddef", "doc", NULL}; | |
276 | ||
277 | gwrap = (struct wrap_graph *)typeobj_graph.tp_alloc(&typeobj_graph, 0); | |
278 | if (!gwrap) | |
279 | return NULL; | |
280 | ||
281 | if (!PyArg_ParseTupleAndKeywords(args, kwds, "s|s", (char **)kwnames, | |
282 | &def, &doc)) | |
283 | return NULL; | |
284 | ||
285 | struct graph *graph = graph_new(); | |
286 | struct cmd_token *token = cmd_token_new(START_TKN, 0, NULL, NULL); | |
287 | graph_new_node(graph, token, (void (*)(void *)) & cmd_token_del); | |
288 | ||
289 | struct cmd_element cmd = {.string = def, .doc = doc}; | |
290 | cmd_graph_parse(graph, &cmd); | |
291 | cmd_graph_names(graph); | |
292 | ||
293 | gwrap->graph = graph; | |
294 | gwrap->definition = strdup(def); | |
295 | gwrap->nodewrappers = calloc(vector_active(graph->nodes), | |
296 | sizeof(gwrap->nodewrappers[0])); | |
297 | return (PyObject *)gwrap; | |
298 | } | |
299 | ||
300 | static PyMethodDef clippy_methods[] = { | |
301 | {"parse", clippy_parse, METH_VARARGS, "Parse a C file"}, | |
302 | {NULL, NULL, 0, NULL}}; | |
303 | ||
304 | #if PY_MAJOR_VERSION >= 3 | |
305 | static struct PyModuleDef pymoddef_clippy = { | |
306 | PyModuleDef_HEAD_INIT, | |
307 | "_clippy", | |
308 | NULL, /* docstring */ | |
309 | -1, | |
310 | clippy_methods, | |
311 | }; | |
312 | #define modcreate() PyModule_Create(&pymoddef_clippy) | |
313 | #define initret(val) return val; | |
314 | #else | |
315 | #define modcreate() Py_InitModule("_clippy", clippy_methods) | |
316 | #define initret(val) \ | |
317 | do { \ | |
318 | if (!val) \ | |
319 | Py_FatalError("initialization failure"); \ | |
320 | return; \ | |
321 | } while (0) | |
322 | #endif | |
323 | ||
324 | PyMODINIT_FUNC command_py_init(void) | |
325 | { | |
326 | PyObject *pymod; | |
327 | ||
328 | if (PyType_Ready(&typeobj_graph_node) < 0) | |
329 | initret(NULL); | |
330 | if (PyType_Ready(&typeobj_graph) < 0) | |
331 | initret(NULL); | |
332 | ||
333 | pymod = modcreate(); | |
334 | if (!pymod) | |
335 | initret(NULL); | |
336 | ||
337 | Py_INCREF(&typeobj_graph_node); | |
338 | PyModule_AddObject(pymod, "GraphNode", (PyObject *)&typeobj_graph_node); | |
339 | Py_INCREF(&typeobj_graph); | |
340 | PyModule_AddObject(pymod, "Graph", (PyObject *)&typeobj_graph); | |
341 | initret(pymod); | |
342 | } |