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