1
2 /* UNIX password file access module */
3
4 // Need limited C API version 3.13 for PyMem_RawRealloc()
5 #include "pyconfig.h" // Py_GIL_DISABLED
6 #ifndef Py_GIL_DISABLED
7 # define Py_LIMITED_API 0x030d0000
8 #endif
9
10 #include "Python.h"
11 #include "posixmodule.h"
12
13 #include <errno.h> // ERANGE
14 #include <pwd.h> // getpwuid()
15 #include <unistd.h> // sysconf()
16
17 #include "clinic/pwdmodule.c.h"
18 /*[clinic input]
19 module pwd
20 [clinic start generated code]*/
21 /*[clinic end generated code: output=da39a3ee5e6b4b0d input=60f628ef356b97b6]*/
22
23 static PyStructSequence_Field struct_pwd_type_fields[] = {
24 {"pw_name", "user name"},
25 {"pw_passwd", "password"},
26 {"pw_uid", "user id"},
27 {"pw_gid", "group id"},
28 {"pw_gecos", "real name"},
29 {"pw_dir", "home directory"},
30 {"pw_shell", "shell program"},
31 {0}
32 };
33
34 PyDoc_STRVAR(struct_passwd__doc__,
35 "pwd.struct_passwd: Results from getpw*() routines.\n\n\
36 This object may be accessed either as a tuple of\n\
37 (pw_name,pw_passwd,pw_uid,pw_gid,pw_gecos,pw_dir,pw_shell)\n\
38 or via the object attributes as named in the above tuple.");
39
40 static PyStructSequence_Desc struct_pwd_type_desc = {
41 "pwd.struct_passwd",
42 struct_passwd__doc__,
43 struct_pwd_type_fields,
44 7,
45 };
46
47 PyDoc_STRVAR(pwd__doc__,
48 "This module provides access to the Unix password database.\n\
49 It is available on all Unix versions.\n\
50 \n\
51 Password database entries are reported as 7-tuples containing the following\n\
52 items from the password database (see `<pwd.h>'), in order:\n\
53 pw_name, pw_passwd, pw_uid, pw_gid, pw_gecos, pw_dir, pw_shell.\n\
54 The uid and gid items are integers, all others are strings. An\n\
55 exception is raised if the entry asked for cannot be found.");
56
57
58 typedef struct {
59 PyTypeObject *StructPwdType;
60 } pwdmodulestate;
61
62 static inline pwdmodulestate*
get_pwd_state(PyObject * module)63 get_pwd_state(PyObject *module)
64 {
65 void *state = PyModule_GetState(module);
66 assert(state != NULL);
67 return (pwdmodulestate *)state;
68 }
69
70 static struct PyModuleDef pwdmodule;
71
72 #define DEFAULT_BUFFER_SIZE 1024
73
74 static PyObject *
mkpwent(PyObject * module,struct passwd * p)75 mkpwent(PyObject *module, struct passwd *p)
76 {
77 PyObject *v = PyStructSequence_New(get_pwd_state(module)->StructPwdType);
78 if (v == NULL) {
79 return NULL;
80 }
81
82 int setIndex = 0;
83
84 #define SET_STRING(VAL) \
85 SET_RESULT((VAL) ? PyUnicode_DecodeFSDefault((VAL)) : Py_NewRef(Py_None))
86
87 #define SET_RESULT(CALL) \
88 do { \
89 PyObject *item = (CALL); \
90 if (item == NULL) { \
91 goto error; \
92 } \
93 PyStructSequence_SetItem(v, setIndex++, item); \
94 } while(0)
95
96 SET_STRING(p->pw_name);
97 #if defined(HAVE_STRUCT_PASSWD_PW_PASSWD) && !defined(__ANDROID__)
98 SET_STRING(p->pw_passwd);
99 #else
100 SET_STRING("");
101 #endif
102 SET_RESULT(_PyLong_FromUid(p->pw_uid));
103 SET_RESULT(_PyLong_FromGid(p->pw_gid));
104 #if defined(HAVE_STRUCT_PASSWD_PW_GECOS)
105 SET_STRING(p->pw_gecos);
106 #else
107 SET_STRING("");
108 #endif
109 SET_STRING(p->pw_dir);
110 SET_STRING(p->pw_shell);
111
112 #undef SET_STRING
113 #undef SET_RESULT
114
115 return v;
116
117 error:
118 Py_DECREF(v);
119 return NULL;
120 }
121
122 /*[clinic input]
123 pwd.getpwuid
124
125 uidobj: object
126 /
127
128 Return the password database entry for the given numeric user ID.
129
130 See `help(pwd)` for more on password database entries.
131 [clinic start generated code]*/
132
133 static PyObject *
pwd_getpwuid(PyObject * module,PyObject * uidobj)134 pwd_getpwuid(PyObject *module, PyObject *uidobj)
135 /*[clinic end generated code: output=c4ee1d4d429b86c4 input=ae64d507a1c6d3e8]*/
136 {
137 PyObject *retval = NULL;
138 uid_t uid;
139 int nomem = 0;
140 struct passwd *p;
141 char *buf = NULL, *buf2 = NULL;
142
143 if (!_Py_Uid_Converter(uidobj, &uid)) {
144 if (PyErr_ExceptionMatches(PyExc_OverflowError))
145 PyErr_Format(PyExc_KeyError,
146 "getpwuid(): uid not found");
147 return NULL;
148 }
149 #ifdef HAVE_GETPWUID_R
150 int status;
151 Py_ssize_t bufsize;
152 /* Note: 'pwd' will be used via pointer 'p' on getpwuid_r success. */
153 struct passwd pwd;
154
155 Py_BEGIN_ALLOW_THREADS
156 bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
157 if (bufsize == -1) {
158 bufsize = DEFAULT_BUFFER_SIZE;
159 }
160
161 while(1) {
162 buf2 = PyMem_RawRealloc(buf, bufsize);
163 if (buf2 == NULL) {
164 p = NULL;
165 nomem = 1;
166 break;
167 }
168 buf = buf2;
169 status = getpwuid_r(uid, &pwd, buf, bufsize, &p);
170 if (status != 0) {
171 p = NULL;
172 }
173 if (p != NULL || status != ERANGE) {
174 break;
175 }
176 if (bufsize > (PY_SSIZE_T_MAX >> 1)) {
177 nomem = 1;
178 break;
179 }
180 bufsize <<= 1;
181 }
182
183 Py_END_ALLOW_THREADS
184 #else
185 p = getpwuid(uid);
186 #endif
187 if (p == NULL) {
188 PyMem_RawFree(buf);
189 if (nomem == 1) {
190 return PyErr_NoMemory();
191 }
192 PyObject *uid_obj = _PyLong_FromUid(uid);
193 if (uid_obj == NULL)
194 return NULL;
195 PyErr_Format(PyExc_KeyError,
196 "getpwuid(): uid not found: %S", uid_obj);
197 Py_DECREF(uid_obj);
198 return NULL;
199 }
200 retval = mkpwent(module, p);
201 #ifdef HAVE_GETPWUID_R
202 PyMem_RawFree(buf);
203 #endif
204 return retval;
205 }
206
207 /*[clinic input]
208 pwd.getpwnam
209
210 name: unicode
211 /
212
213 Return the password database entry for the given user name.
214
215 See `help(pwd)` for more on password database entries.
216 [clinic start generated code]*/
217
218 static PyObject *
pwd_getpwnam_impl(PyObject * module,PyObject * name)219 pwd_getpwnam_impl(PyObject *module, PyObject *name)
220 /*[clinic end generated code: output=359ce1ddeb7a824f input=a6aeb5e3447fb9e0]*/
221 {
222 char *buf = NULL, *buf2 = NULL, *name_chars;
223 int nomem = 0;
224 struct passwd *p;
225 PyObject *bytes, *retval = NULL;
226
227 if ((bytes = PyUnicode_EncodeFSDefault(name)) == NULL)
228 return NULL;
229 /* check for embedded null bytes */
230 if (PyBytes_AsStringAndSize(bytes, &name_chars, NULL) == -1)
231 goto out;
232 #ifdef HAVE_GETPWNAM_R
233 int status;
234 Py_ssize_t bufsize;
235 /* Note: 'pwd' will be used via pointer 'p' on getpwnam_r success. */
236 struct passwd pwd;
237
238 Py_BEGIN_ALLOW_THREADS
239 bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
240 if (bufsize == -1) {
241 bufsize = DEFAULT_BUFFER_SIZE;
242 }
243
244 while(1) {
245 buf2 = PyMem_RawRealloc(buf, bufsize);
246 if (buf2 == NULL) {
247 p = NULL;
248 nomem = 1;
249 break;
250 }
251 buf = buf2;
252 status = getpwnam_r(name_chars, &pwd, buf, bufsize, &p);
253 if (status != 0) {
254 p = NULL;
255 }
256 if (p != NULL || status != ERANGE) {
257 break;
258 }
259 if (bufsize > (PY_SSIZE_T_MAX >> 1)) {
260 nomem = 1;
261 break;
262 }
263 bufsize <<= 1;
264 }
265
266 Py_END_ALLOW_THREADS
267 #else
268 p = getpwnam(name_chars);
269 #endif
270 if (p == NULL) {
271 if (nomem == 1) {
272 PyErr_NoMemory();
273 }
274 else {
275 PyErr_Format(PyExc_KeyError,
276 "getpwnam(): name not found: %R", name);
277 }
278 goto out;
279 }
280 retval = mkpwent(module, p);
281 out:
282 PyMem_RawFree(buf);
283 Py_DECREF(bytes);
284 return retval;
285 }
286
287 #ifdef HAVE_GETPWENT
288 /*[clinic input]
289 pwd.getpwall
290
291 Return a list of all available password database entries, in arbitrary order.
292
293 See help(pwd) for more on password database entries.
294 [clinic start generated code]*/
295
296 static PyObject *
pwd_getpwall_impl(PyObject * module)297 pwd_getpwall_impl(PyObject *module)
298 /*[clinic end generated code: output=4853d2f5a0afac8a input=d7ecebfd90219b85]*/
299 {
300 PyObject *d;
301 struct passwd *p;
302 if ((d = PyList_New(0)) == NULL)
303 return NULL;
304 setpwent();
305 while ((p = getpwent()) != NULL) {
306 PyObject *v = mkpwent(module, p);
307 if (v == NULL || PyList_Append(d, v) != 0) {
308 Py_XDECREF(v);
309 Py_DECREF(d);
310 endpwent();
311 return NULL;
312 }
313 Py_DECREF(v);
314 }
315 endpwent();
316 return d;
317 }
318 #endif
319
320 static PyMethodDef pwd_methods[] = {
321 PWD_GETPWUID_METHODDEF
322 PWD_GETPWNAM_METHODDEF
323 #ifdef HAVE_GETPWENT
324 PWD_GETPWALL_METHODDEF
325 #endif
326 {NULL, NULL} /* sentinel */
327 };
328
329 static int
pwdmodule_exec(PyObject * module)330 pwdmodule_exec(PyObject *module)
331 {
332 pwdmodulestate *state = get_pwd_state(module);
333
334 state->StructPwdType = PyStructSequence_NewType(&struct_pwd_type_desc);
335 if (state->StructPwdType == NULL) {
336 return -1;
337 }
338 if (PyModule_AddType(module, state->StructPwdType) < 0) {
339 return -1;
340 }
341 return 0;
342 }
343
344 static PyModuleDef_Slot pwdmodule_slots[] = {
345 {Py_mod_exec, pwdmodule_exec},
346 {Py_mod_multiple_interpreters, Py_MOD_PER_INTERPRETER_GIL_SUPPORTED},
347 {Py_mod_gil, Py_MOD_GIL_NOT_USED},
348 {0, NULL}
349 };
350
pwdmodule_traverse(PyObject * m,visitproc visit,void * arg)351 static int pwdmodule_traverse(PyObject *m, visitproc visit, void *arg) {
352 Py_VISIT(get_pwd_state(m)->StructPwdType);
353 return 0;
354 }
pwdmodule_clear(PyObject * m)355 static int pwdmodule_clear(PyObject *m) {
356 Py_CLEAR(get_pwd_state(m)->StructPwdType);
357 return 0;
358 }
pwdmodule_free(void * m)359 static void pwdmodule_free(void *m) {
360 pwdmodule_clear((PyObject *)m);
361 }
362
363 static struct PyModuleDef pwdmodule = {
364 PyModuleDef_HEAD_INIT,
365 .m_name = "pwd",
366 .m_doc = pwd__doc__,
367 .m_size = sizeof(pwdmodulestate),
368 .m_methods = pwd_methods,
369 .m_slots = pwdmodule_slots,
370 .m_traverse = pwdmodule_traverse,
371 .m_clear = pwdmodule_clear,
372 .m_free = pwdmodule_free,
373 };
374
375
376 PyMODINIT_FUNC
PyInit_pwd(void)377 PyInit_pwd(void)
378 {
379 return PyModuleDef_Init(&pwdmodule);
380 }
381