newlib-cygwin/winsup/cygwin/passwd.cc

289 lines
6.1 KiB
C++

/* passwd.cc: getpwnam () and friends
Copyright 1996, 1997, 1998 Cygnus Solutions.
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include "winsup.h"
#include <stdlib.h>
#include <pwd.h>
#include <stdio.h>
#include <errno.h>
#include "cygerrno.h"
#include "fhandler.h"
#include "dtable.h"
#include "sync.h"
#include "sigproc.h"
#include "pinfo.h"
#include <sys/termios.h>
/* Read /etc/passwd only once for better performance. This is done
on the first call that needs information from it. */
static struct passwd *passwd_buf = NULL; /* passwd contents in memory */
static int curr_lines = 0;
static int max_lines = 0;
/* Set to loaded when /etc/passwd has been read in by read_etc_passwd ().
Set to emulated if passwd is emulated. */
/* Functions in this file need to check the value of passwd_state
and read in the password file if it isn't set. */
enum pwd_state {
uninitialized = 0,
emulated,
loaded
};
static pwd_state passwd_state = uninitialized;
/* Position in the passwd cache */
#ifdef _MT_SAFE
#define pw_pos _reent_winsup()->_pw_pos
#else
static int pw_pos = 0;
#endif
/* Remove a : teminated string from the buffer, and increment the pointer */
static char *
grab_string (char **p)
{
char *src = *p;
char *res = src;
while (*src && *src != ':' && *src != '\n')
src++;
if (*src == ':')
{
*src = 0;
src++;
}
*p = src;
return res;
}
/* same, for ints */
static int
grab_int (char **p)
{
char *src = *p;
int val = strtol (src, NULL, 10);
while (*src && *src != ':' && *src != '\n')
src++;
if (*src == ':')
src++;
*p = src;
return val;
}
/* Parse /etc/passwd line into passwd structure. */
void
parse_pwd (struct passwd &res, char *buf)
{
/* Allocate enough room for the passwd struct and all the strings
in it in one go */
size_t len = strlen (buf);
char *mybuf = (char *) malloc (len + 1);
(void) memcpy (mybuf, buf, len + 1);
if (mybuf[--len] == '\n')
mybuf[len] = '\0';
res.pw_name = strlwr(grab_string (&mybuf));
res.pw_passwd = grab_string (&mybuf);
res.pw_uid = grab_int (&mybuf);
res.pw_gid = grab_int (&mybuf);
res.pw_comment = 0;
res.pw_gecos = grab_string (&mybuf);
res.pw_dir = grab_string (&mybuf);
res.pw_shell = grab_string (&mybuf);
}
/* Add one line from /etc/passwd into the password cache */
static void
add_pwd_line (char *line)
{
if (curr_lines >= max_lines)
{
max_lines += 10;
passwd_buf = (struct passwd *) realloc (passwd_buf, max_lines * sizeof (struct passwd));
}
parse_pwd (passwd_buf[curr_lines++], line);
}
/* Read in /etc/passwd and save contents in the password cache.
This sets passwd_state to loaded or emulated so functions in this file can
tell that /etc/passwd has been read in or will be emulated. */
void
read_etc_passwd ()
{
extern int passwd_sem;
char linebuf[1024];
++passwd_sem;
FILE *f = fopen ("/etc/passwd", "rt");
--passwd_sem;
if (f)
{
while (fgets (linebuf, sizeof (linebuf), f) != NULL)
{
if (strlen (linebuf))
add_pwd_line (linebuf);
}
fclose (f);
passwd_state = loaded;
}
else
{
debug_printf ("Emulating /etc/passwd");
char user_name [ MAX_USER_NAME ];
DWORD user_name_len = MAX_USER_NAME;
if (! GetUserNameA (user_name, &user_name_len))
{
strncpy (user_name, "Administrator", MAX_USER_NAME);
debug_printf ("Failed to get current user name. %E");
}
snprintf (linebuf, sizeof (linebuf), "%s::%u:%u::%s:/bin/sh", user_name,
DEFAULT_UID, DEFAULT_GID, getenv ("HOME") ?: "/");
add_pwd_line (linebuf);
passwd_state = emulated;
}
}
/* Cygwin internal */
static struct passwd *
search_for (uid_t uid, const char *name)
{
struct passwd *res = 0;
struct passwd *default_pw = 0;
for (int i = 0; i < curr_lines; i++)
{
res = passwd_buf + i;
if (res->pw_uid == DEFAULT_UID)
default_pw = res;
/* on Windows NT user names are case-insensitive */
if (name)
{
if (strcasematch (name, res->pw_name))
return res;
}
else if (uid == res->pw_uid)
return res;
}
/* Return default passwd entry if passwd is emulated or it's a
request for the current user. */
if (passwd_state != loaded
|| (!name && uid == myself->uid)
|| (name && strcasematch(name, myself->username)))
return default_pw;
return NULL;
}
extern "C" struct passwd *
getpwuid (uid_t uid)
{
if (passwd_state == uninitialized)
read_etc_passwd();
return search_for (uid, 0);
}
extern "C" struct passwd *
getpwnam (const char *name)
{
if (passwd_state == uninitialized)
read_etc_passwd();
return search_for (0, name);
}
extern "C" struct passwd *
getpwent (void)
{
if (passwd_state == uninitialized)
read_etc_passwd();
if (pw_pos < curr_lines)
return passwd_buf + pw_pos++;
return NULL;
}
extern "C" struct passwd *
getpwduid (uid_t)
{
if (passwd_state == uninitialized)
read_etc_passwd();
return NULL;
}
extern "C" void
setpwent (void)
{
if (passwd_state == uninitialized)
read_etc_passwd();
pw_pos = 0;
}
extern "C" void
endpwent (void)
{
if (passwd_state == uninitialized)
read_etc_passwd();
pw_pos = 0;
}
extern "C" int
setpassent ()
{
if (passwd_state == uninitialized)
read_etc_passwd();
return 0;
}
extern "C" char *
getpass (const char * prompt)
{
#ifdef _MT_SAFE
char *pass=_reent_winsup()->_pass;
#else
static char pass[_PASSWORD_LEN];
#endif
struct termios ti, newti;
if (passwd_state == uninitialized)
read_etc_passwd();
if (fdtab.not_open (0))
{
set_errno (EBADF);
pass[0] = '\0';
}
else
{
fhandler_base *fhstdin = fdtab[0];
fhstdin->tcgetattr (&ti);
newti = ti;
newti.c_lflag &= ~ECHO;
fhstdin->tcsetattr (TCSANOW, &newti);
fputs (prompt, stderr);
fgets (pass, _PASSWORD_LEN, stdin);
fprintf (stderr, "\n");
for (int i=0; pass[i]; i++)
if (pass[i] == '\r' || pass[i] == '\n')
pass[i] = '\0';
fhstdin->tcsetattr (TCSANOW, &ti);
}
return pass;
}