/* UNIX password file access module */

#include "Python.h"
#include "posixmodule.h"

#include <pwd.h>

#include "clinic/pwdmodule.c.h"
/*[clinic input]
module pwd
[clinic start generated code]*/
/*[clinic end generated code: output=da39a3ee5e6b4b0d input=60f628ef356b97b6]*/

static PyStructSequence_Field struct_pwd_type_fields[] = {
 {"pw_name", "user name"},
 {"pw_passwd", "password"},
 {"pw_uid", "user id"},
 {"pw_gid", "group id"},
 {"pw_gecos", "real name"},
 {"pw_dir", "home directory"},
 {"pw_shell", "shell program"},
 {0}
};

PyDoc_STRVAR(struct_passwd__doc__,
"pwd.struct_passwd: Results from getpw*() routines.\n\n\
This object may be accessed either as a tuple of\n\
 (pw_name,pw_passwd,pw_uid,pw_gid,pw_gecos,pw_dir,pw_shell)\n\
or via the object attributes as named in the above tuple.");

static PyStructSequence_Desc struct_pwd_type_desc = {
 "pwd.struct_passwd",
 struct_passwd__doc__,
 struct_pwd_type_fields,
 7,
};

PyDoc_STRVAR(pwd__doc__,
"This module provides access to the Unix password database.\n\
It is available on all Unix versions.\n\
\n\
Password database entries are reported as 7-tuples containing the following\n\
items from the password database (see `<pwd.h>'), in order:\n\
pw_name, pw_passwd, pw_uid, pw_gid, pw_gecos, pw_dir, pw_shell.\n\
The uid and gid items are integers, all others are strings. An\n\
exception is raised if the entry asked for cannot be found.");


static int initialized;
static PyTypeObject StructPwdType;

#define DEFAULT_BUFFER_SIZE 1024

static void
sets(PyObject *v, int i, const char* val)
{
 if (val) {
 PyObject *o = PyUnicode_DecodeFSDefault(val);
 PyStructSequence_SET_ITEM(v, i, o);
 }
 else {
 PyStructSequence_SET_ITEM(v, i, Py_None);
 Py_INCREF(Py_None);
 }
}

static PyObject *
mkpwent(struct passwd *p)
{
 int setIndex = 0;
 PyObject *v = PyStructSequence_New(&StructPwdType);
 if (v == NULL)
 return NULL;

#define SETI(i,val) PyStructSequence_SET_ITEM(v, i, PyLong_FromLong((long) val))
#define SETS(i,val) sets(v, i, val)

 SETS(setIndex++, p->pw_name);
#if defined(HAVE_STRUCT_PASSWD_PW_PASSWD) && !defined(__ANDROID__)
 SETS(setIndex++, p->pw_passwd);
#else
 SETS(setIndex++, "");
#endif
 PyStructSequence_SET_ITEM(v, setIndex++, _PyLong_FromUid(p->pw_uid));
 PyStructSequence_SET_ITEM(v, setIndex++, _PyLong_FromGid(p->pw_gid));
#if defined(HAVE_STRUCT_PASSWD_PW_GECOS)
 SETS(setIndex++, p->pw_gecos);
#else
 SETS(setIndex++, "");
#endif
 SETS(setIndex++, p->pw_dir);
 SETS(setIndex++, p->pw_shell);

#undef SETS
#undef SETI

 if (PyErr_Occurred()) {
 Py_XDECREF(v);
 return NULL;
 }

 return v;
}

/*[clinic input]
pwd.getpwuid

 uidobj: object
 /

Return the password database entry for the given numeric user ID.

See `help(pwd)` for more on password database entries.
[clinic start generated code]*/

static PyObject *
pwd_getpwuid(PyObject *module, PyObject *uidobj)
/*[clinic end generated code: output=c4ee1d4d429b86c4 input=ae64d507a1c6d3e8]*/
{
 PyObject *retval = NULL;
 uid_t uid;
 int nomem = 0;
 struct passwd *p;
 char *buf = NULL, *buf2 = NULL;

 if (!_Py_Uid_Converter(uidobj, &uid)) {
 if (PyErr_ExceptionMatches(PyExc_OverflowError))
 PyErr_Format(PyExc_KeyError,
 "getpwuid(): uid not found");
 return NULL;
 }
#ifdef HAVE_GETPWUID_R
 int status;
 Py_ssize_t bufsize;
 /* Note: 'pwd' will be used via pointer 'p' on getpwuid_r success. */
 struct passwd pwd;

 Py_BEGIN_ALLOW_THREADS
 bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
 if (bufsize == -1) {
 bufsize = DEFAULT_BUFFER_SIZE;
 }

 while(1) {
 buf2 = PyMem_RawRealloc(buf, bufsize);
 if (buf2 == NULL) {
 p = NULL;
 nomem = 1;
 break;
 }
 buf = buf2;
 status = getpwuid_r(uid, &pwd, buf, bufsize, &p);
 if (status != 0) {
 p = NULL;
 }
 if (p != NULL || status != ERANGE) {
 break;
 }
 if (bufsize > (PY_SSIZE_T_MAX >> 1)) {
 nomem = 1;
 break;
 }
 bufsize <<= 1;
 }

 Py_END_ALLOW_THREADS
#else
 p = getpwuid(uid);
#endif
 if (p == NULL) {
 PyMem_RawFree(buf);
 if (nomem == 1) {
 return PyErr_NoMemory();
 }
 PyObject *uid_obj = _PyLong_FromUid(uid);
 if (uid_obj == NULL)
 return NULL;
 PyErr_Format(PyExc_KeyError,
 "getpwuid(): uid not found: %S", uid_obj);
 Py_DECREF(uid_obj);
 return NULL;
 }
 retval = mkpwent(p);
#ifdef HAVE_GETPWUID_R
 PyMem_RawFree(buf);
#endif
 return retval;
}

/*[clinic input]
pwd.getpwnam

 name: unicode
 /

Return the password database entry for the given user name.

See `help(pwd)` for more on password database entries.
[clinic start generated code]*/

static PyObject *
pwd_getpwnam_impl(PyObject *module, PyObject *name)
/*[clinic end generated code: output=359ce1ddeb7a824f input=a6aeb5e3447fb9e0]*/
{
 char *buf = NULL, *buf2 = NULL, *name_chars;
 int nomem = 0;
 struct passwd *p;
 PyObject *bytes, *retval = NULL;

 if ((bytes = PyUnicode_EncodeFSDefault(name)) == NULL)
 return NULL;
 /* check for embedded null bytes */
 if (PyBytes_AsStringAndSize(bytes, &name_chars, NULL) == -1)
 goto out;
#ifdef HAVE_GETPWNAM_R
 int status;
 Py_ssize_t bufsize;
 /* Note: 'pwd' will be used via pointer 'p' on getpwnam_r success. */
 struct passwd pwd;

 Py_BEGIN_ALLOW_THREADS
 bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
 if (bufsize == -1) {
 bufsize = DEFAULT_BUFFER_SIZE;
 }

 while(1) {
 buf2 = PyMem_RawRealloc(buf, bufsize);
 if (buf2 == NULL) {
 p = NULL;
 nomem = 1;
 break;
 }
 buf = buf2;
 status = getpwnam_r(name_chars, &pwd, buf, bufsize, &p);
 if (status != 0) {
 p = NULL;
 }
 if (p != NULL || status != ERANGE) {
 break;
 }
 if (bufsize > (PY_SSIZE_T_MAX >> 1)) {
 nomem = 1;
 break;
 }
 bufsize <<= 1;
 }

 Py_END_ALLOW_THREADS
#else
 p = getpwnam(name_chars);
#endif
 if (p == NULL) {
 if (nomem == 1) {
 PyErr_NoMemory();
 }
 else {
 PyErr_Format(PyExc_KeyError,
 "getpwnam(): name not found: %R", name);
 }
 goto out;
 }
 retval = mkpwent(p);
out:
 PyMem_RawFree(buf);
 Py_DECREF(bytes);
 return retval;
}

#ifdef HAVE_GETPWENT
/*[clinic input]
pwd.getpwall

Return a list of all available password database entries, in arbitrary order.

See help(pwd) for more on password database entries.
[clinic start generated code]*/

static PyObject *
pwd_getpwall_impl(PyObject *module)
/*[clinic end generated code: output=4853d2f5a0afac8a input=d7ecebfd90219b85]*/
{
 PyObject *d;
 struct passwd *p;
 if ((d = PyList_New(0)) == NULL)
 return NULL;
 setpwent();
 while ((p = getpwent()) != NULL) {
 PyObject *v = mkpwent(p);
 if (v == NULL || PyList_Append(d, v) != 0) {
 Py_XDECREF(v);
 Py_DECREF(d);
 endpwent();
 return NULL;
 }
 Py_DECREF(v);
 }
 endpwent();
 return d;
}
#endif

static PyMethodDef pwd_methods[] = {
 PWD_GETPWUID_METHODDEF
 PWD_GETPWNAM_METHODDEF
#ifdef HAVE_GETPWENT
 PWD_GETPWALL_METHODDEF
#endif
 {NULL, NULL} /* sentinel */
};

static struct PyModuleDef pwdmodule = {
 PyModuleDef_HEAD_INIT,
 "pwd",
 pwd__doc__,
 -1,
 pwd_methods,
 NULL,
 NULL,
 NULL,
 NULL
};


PyMODINIT_FUNC
PyInit_pwd(void)
{
 PyObject *m;
 m = PyModule_Create(&pwdmodule);
 if (m == NULL)
 return NULL;

 if (!initialized) {
 if (PyStructSequence_InitType2(&StructPwdType,
 &struct_pwd_type_desc) < 0)
 return NULL;
 initialized = 1;
 }
 Py_INCREF((PyObject *) &StructPwdType);
 PyModule_AddObject(m, "struct_passwd", (PyObject *) &StructPwdType);
 return m;
}