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 static struct PyModuleDef pwdmodule;
63
64 #define DEFAULT_BUFFER_SIZE 1024
65
66 static void
sets(PyObject * v,int i,const char * val)67 sets(PyObject *v, int i, const char* val)
68 {
69 if (val) {
70 PyObject *o = PyUnicode_DecodeFSDefault(val);
71 PyStructSequence_SET_ITEM(v, i, o);
72 }
73 else {
74 PyStructSequence_SET_ITEM(v, i, Py_None);
75 Py_INCREF(Py_None);
76 }
77 }
78
79 static PyObject *
mkpwent(PyObject * module,struct passwd * p)80 mkpwent(PyObject *module, struct passwd *p)
81 {
82 int setIndex = 0;
83 PyObject *v = PyStructSequence_New(get_pwd_state(module)->StructPwdType);
84 if (v == NULL)
85 return NULL;
86
87 #define SETI(i,val) PyStructSequence_SET_ITEM(v, i, PyLong_FromLong((long) val))
88 #define SETS(i,val) sets(v, i, val)
89
90 SETS(setIndex++, p->pw_name);
91 #if defined(HAVE_STRUCT_PASSWD_PW_PASSWD) && !defined(__ANDROID__)
92 SETS(setIndex++, p->pw_passwd);
93 #else
94 SETS(setIndex++, "");
95 #endif
96 PyStructSequence_SET_ITEM(v, setIndex++, _PyLong_FromUid(p->pw_uid));
97 PyStructSequence_SET_ITEM(v, setIndex++, _PyLong_FromGid(p->pw_gid));
98 #if defined(HAVE_STRUCT_PASSWD_PW_GECOS)
99 SETS(setIndex++, p->pw_gecos);
100 #else
101 SETS(setIndex++, "");
102 #endif
103 SETS(setIndex++, p->pw_dir);
104 SETS(setIndex++, p->pw_shell);
105
106 #undef SETS
107 #undef SETI
108
109 if (PyErr_Occurred()) {
110 Py_XDECREF(v);
111 return NULL;
112 }
113
114 return v;
115 }
116
117 /*[clinic input]
118 pwd.getpwuid
119
120 uidobj: object
121 /
122
123 Return the password database entry for the given numeric user ID.
124
125 See `help(pwd)` for more on password database entries.
126 [clinic start generated code]*/
127
128 static PyObject *
pwd_getpwuid(PyObject * module,PyObject * uidobj)129 pwd_getpwuid(PyObject *module, PyObject *uidobj)
130 /*[clinic end generated code: output=c4ee1d4d429b86c4 input=ae64d507a1c6d3e8]*/
131 {
132 PyObject *retval = NULL;
133 uid_t uid;
134 int nomem = 0;
135 struct passwd *p;
136 char *buf = NULL, *buf2 = NULL;
137
138 if (!_Py_Uid_Converter(uidobj, &uid)) {
139 if (PyErr_ExceptionMatches(PyExc_OverflowError))
140 PyErr_Format(PyExc_KeyError,
141 "getpwuid(): uid not found");
142 return NULL;
143 }
144 #ifdef HAVE_GETPWUID_R
145 int status;
146 Py_ssize_t bufsize;
147 /* Note: 'pwd' will be used via pointer 'p' on getpwuid_r success. */
148 struct passwd pwd;
149
150 Py_BEGIN_ALLOW_THREADS
151 bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
152 if (bufsize == -1) {
153 bufsize = DEFAULT_BUFFER_SIZE;
154 }
155
156 while(1) {
157 buf2 = PyMem_RawRealloc(buf, bufsize);
158 if (buf2 == NULL) {
159 p = NULL;
160 nomem = 1;
161 break;
162 }
163 buf = buf2;
164 status = getpwuid_r(uid, &pwd, buf, bufsize, &p);
165 if (status != 0) {
166 p = NULL;
167 }
168 if (p != NULL || status != ERANGE) {
169 break;
170 }
171 if (bufsize > (PY_SSIZE_T_MAX >> 1)) {
172 nomem = 1;
173 break;
174 }
175 bufsize <<= 1;
176 }
177
178 Py_END_ALLOW_THREADS
179 #else
180 p = getpwuid(uid);
181 #endif
182 if (p == NULL) {
183 PyMem_RawFree(buf);
184 if (nomem == 1) {
185 return PyErr_NoMemory();
186 }
187 PyObject *uid_obj = _PyLong_FromUid(uid);
188 if (uid_obj == NULL)
189 return NULL;
190 PyErr_Format(PyExc_KeyError,
191 "getpwuid(): uid not found: %S", uid_obj);
192 Py_DECREF(uid_obj);
193 return NULL;
194 }
195 retval = mkpwent(module, p);
196 #ifdef HAVE_GETPWUID_R
197 PyMem_RawFree(buf);
198 #endif
199 return retval;
200 }
201
202 /*[clinic input]
203 pwd.getpwnam
204
205 name: unicode
206 /
207
208 Return the password database entry for the given user name.
209
210 See `help(pwd)` for more on password database entries.
211 [clinic start generated code]*/
212
213 static PyObject *
pwd_getpwnam_impl(PyObject * module,PyObject * name)214 pwd_getpwnam_impl(PyObject *module, PyObject *name)
215 /*[clinic end generated code: output=359ce1ddeb7a824f input=a6aeb5e3447fb9e0]*/
216 {
217 char *buf = NULL, *buf2 = NULL, *name_chars;
218 int nomem = 0;
219 struct passwd *p;
220 PyObject *bytes, *retval = NULL;
221
222 if ((bytes = PyUnicode_EncodeFSDefault(name)) == NULL)
223 return NULL;
224 /* check for embedded null bytes */
225 if (PyBytes_AsStringAndSize(bytes, &name_chars, NULL) == -1)
226 goto out;
227 #ifdef HAVE_GETPWNAM_R
228 int status;
229 Py_ssize_t bufsize;
230 /* Note: 'pwd' will be used via pointer 'p' on getpwnam_r success. */
231 struct passwd pwd;
232
233 Py_BEGIN_ALLOW_THREADS
234 bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
235 if (bufsize == -1) {
236 bufsize = DEFAULT_BUFFER_SIZE;
237 }
238
239 while(1) {
240 buf2 = PyMem_RawRealloc(buf, bufsize);
241 if (buf2 == NULL) {
242 p = NULL;
243 nomem = 1;
244 break;
245 }
246 buf = buf2;
247 status = getpwnam_r(name_chars, &pwd, buf, bufsize, &p);
248 if (status != 0) {
249 p = NULL;
250 }
251 if (p != NULL || status != ERANGE) {
252 break;
253 }
254 if (bufsize > (PY_SSIZE_T_MAX >> 1)) {
255 nomem = 1;
256 break;
257 }
258 bufsize <<= 1;
259 }
260
261 Py_END_ALLOW_THREADS
262 #else
263 p = getpwnam(name_chars);
264 #endif
265 if (p == NULL) {
266 if (nomem == 1) {
267 PyErr_NoMemory();
268 }
269 else {
270 PyErr_Format(PyExc_KeyError,
271 "getpwnam(): name not found: %R", name);
272 }
273 goto out;
274 }
275 retval = mkpwent(module, p);
276 out:
277 PyMem_RawFree(buf);
278 Py_DECREF(bytes);
279 return retval;
280 }
281
282 #ifdef HAVE_GETPWENT
283 /*[clinic input]
284 pwd.getpwall
285
286 Return a list of all available password database entries, in arbitrary order.
287
288 See help(pwd) for more on password database entries.
289 [clinic start generated code]*/
290
291 static PyObject *
pwd_getpwall_impl(PyObject * module)292 pwd_getpwall_impl(PyObject *module)
293 /*[clinic end generated code: output=4853d2f5a0afac8a input=d7ecebfd90219b85]*/
294 {
295 PyObject *d;
296 struct passwd *p;
297 if ((d = PyList_New(0)) == NULL)
298 return NULL;
299 setpwent();
300 while ((p = getpwent()) != NULL) {
301 PyObject *v = mkpwent(module, p);
302 if (v == NULL || PyList_Append(d, v) != 0) {
303 Py_XDECREF(v);
304 Py_DECREF(d);
305 endpwent();
306 return NULL;
307 }
308 Py_DECREF(v);
309 }
310 endpwent();
311 return d;
312 }
313 #endif
314
315 static PyMethodDef pwd_methods[] = {
316 PWD_GETPWUID_METHODDEF
317 PWD_GETPWNAM_METHODDEF
318 #ifdef HAVE_GETPWENT
319 PWD_GETPWALL_METHODDEF
320 #endif
321 {NULL, NULL} /* sentinel */
322 };
323
324 static int
pwdmodule_exec(PyObject * module)325 pwdmodule_exec(PyObject *module)
326 {
327 pwdmodulestate *state = get_pwd_state(module);
328
329 state->StructPwdType = PyStructSequence_NewType(&struct_pwd_type_desc);
330 if (state->StructPwdType == NULL) {
331 return -1;
332 }
333 if (PyModule_AddType(module, state->StructPwdType) < 0) {
334 return -1;
335 }
336 return 0;
337 }
338
339 static PyModuleDef_Slot pwdmodule_slots[] = {
340 {Py_mod_exec, pwdmodule_exec},
341 {0, NULL}
342 };
343
pwdmodule_traverse(PyObject * m,visitproc visit,void * arg)344 static int pwdmodule_traverse(PyObject *m, visitproc visit, void *arg) {
345 Py_VISIT(get_pwd_state(m)->StructPwdType);
346 return 0;
347 }
pwdmodule_clear(PyObject * m)348 static int pwdmodule_clear(PyObject *m) {
349 Py_CLEAR(get_pwd_state(m)->StructPwdType);
350 return 0;
351 }
pwdmodule_free(void * m)352 static void pwdmodule_free(void *m) {
353 pwdmodule_clear((PyObject *)m);
354 }
355
356 static struct PyModuleDef pwdmodule = {
357 PyModuleDef_HEAD_INIT,
358 .m_name = "pwd",
359 .m_doc = pwd__doc__,
360 .m_size = sizeof(pwdmodulestate),
361 .m_methods = pwd_methods,
362 .m_slots = pwdmodule_slots,
363 .m_traverse = pwdmodule_traverse,
364 .m_clear = pwdmodule_clear,
365 .m_free = pwdmodule_free,
366 };
367
368
369 PyMODINIT_FUNC
PyInit_pwd(void)370 PyInit_pwd(void)
371 {
372 return PyModuleDef_Init(&pwdmodule);
373 }
374