newlib/winsup/cygwin/passwd.cc

416 lines
9.9 KiB
C++

/* passwd.cc: getpwnam () and friends
Copyright 1996, 1997, 1998, 2001, 2002, 2003 Red Hat, Inc.
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 "security.h"
#include "fhandler.h"
#include "path.h"
#include "dtable.h"
#include "pinfo.h"
#include "cygheap.h"
#include <sys/termios.h>
#include "pwdgrp.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; /* passwd contents in memory */
static int curr_lines;
static int max_lines;
static pwdgrp_check passwd_state;
/* 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++;
if (*src == ':')
{
*src = 0;
src++;
}
*p = src;
return res;
}
/* same, for ints */
static unsigned int
grab_int (char **p)
{
char *src = *p;
unsigned int val = strtoul (src, p, 10);
*p = (*p == src || **p != ':') ? almost_null : *p + 1;
return val;
}
/* Parse /etc/passwd line into passwd structure. */
static int
parse_pwd (struct passwd &res, char *buf)
{
/* Allocate enough room for the passwd struct and all the strings
in it in one go */
res.pw_name = grab_string (&buf);
res.pw_passwd = grab_string (&buf);
res.pw_uid = grab_int (&buf);
res.pw_gid = grab_int (&buf);
if (!*buf)
return 0;
res.pw_comment = 0;
res.pw_gecos = grab_string (&buf);
res.pw_dir = grab_string (&buf);
res.pw_shell = grab_string (&buf);
return 1;
}
/* 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));
}
if (parse_pwd (passwd_buf[curr_lines], line))
curr_lines++;
}
class passwd_lock
{
bool armed;
static NO_COPY pthread_mutex_t mutex;
public:
passwd_lock (bool doit)
{
if (doit)
pthread_mutex_lock (&mutex);
armed = doit;
}
~passwd_lock ()
{
if (armed)
pthread_mutex_unlock (&mutex);
}
};
pthread_mutex_t NO_COPY passwd_lock::mutex = (pthread_mutex_t) PTHREAD_MUTEX_INITIALIZER;
/* 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. */
static void
read_etc_passwd ()
{
static pwdgrp_read pr;
/* A mutex is ok for speed here - pthreads will use critical sections not
* mutexes for non-shared mutexes in the future. Also, this function will
* at most be called once from each thread, after that the passwd_state
* test will succeed */
passwd_lock here (cygwin_finished_initializing);
/* if we got blocked by the mutex, then etc_passwd may have been processed */
if (passwd_state.isinitializing ())
{
curr_lines = 0;
if (pr.open ("/etc/passwd"))
{
char *line;
while ((line = pr.gets ()) != NULL)
add_pwd_line (line);
passwd_state.set_last_modified (pr.get_fhandle (), pr.get_fname ());
pr.close ();
debug_printf ("Read /etc/passwd, %d lines", curr_lines);
}
passwd_state = loaded;
static char linebuf[1024];
char strbuf[128] = "";
BOOL searchentry = TRUE;
__uid32_t default_uid = DEFAULT_UID;
struct passwd *pw;
if (wincap.has_security ())
{
cygsid tu = cygheap->user.sid ();
tu.string (strbuf);
if (myself->uid == ILLEGAL_UID
&& (searchentry = !internal_getpwsid (tu)))
default_uid = DEFAULT_UID_NT;
}
else if (myself->uid == ILLEGAL_UID)
searchentry = !internal_getpwuid (DEFAULT_UID);
if (searchentry &&
(!(pw = internal_getpwnam (cygheap->user.name ())) ||
(myself->uid != ILLEGAL_UID &&
myself->uid != (__uid32_t) pw->pw_uid &&
!internal_getpwuid (myself->uid))))
{
snprintf (linebuf, sizeof (linebuf), "%s:*:%lu:%lu:,%s:%s:/bin/sh",
cygheap->user.name (),
myself->uid == ILLEGAL_UID ? default_uid : myself->uid,
myself->gid,
strbuf, getenv ("HOME") ?: "/");
debug_printf ("Completing /etc/passwd: %s", linebuf);
add_pwd_line (linebuf);
}
}
return;
}
struct passwd *
internal_getpwsid (cygsid &sid)
{
struct passwd *pw;
char *ptr1, *ptr2, *endptr;
char sid_string[128] = {0,','};
if (passwd_state.isuninitialized ())
read_etc_passwd ();
if (sid.string (sid_string + 2))
{
endptr = strchr (sid_string + 2, 0) - 1;
for (int i = 0; i < curr_lines; i++)
if ((pw = passwd_buf + i)->pw_dir > pw->pw_gecos + 8)
for (ptr1 = endptr, ptr2 = pw->pw_dir - 2;
*ptr1 == *ptr2; ptr2--)
if (!*--ptr1)
return pw;
}
return NULL;
}
struct passwd *
internal_getpwuid (__uid32_t uid, BOOL check)
{
if (passwd_state.isuninitialized ()
|| (check && passwd_state.isinitializing ()))
read_etc_passwd ();
for (int i = 0; i < curr_lines; i++)
if (uid == (__uid32_t) passwd_buf[i].pw_uid)
return passwd_buf + i;
return NULL;
}
struct passwd *
internal_getpwnam (const char *name, BOOL check)
{
if (passwd_state.isuninitialized ()
|| (check && passwd_state.isinitializing ()))
read_etc_passwd ();
for (int i = 0; i < curr_lines; i++)
/* on Windows NT user names are case-insensitive */
if (strcasematch (name, passwd_buf[i].pw_name))
return passwd_buf + i;
return NULL;
}
extern "C" struct passwd *
getpwuid32 (__uid32_t uid)
{
struct passwd *temppw = internal_getpwuid (uid, TRUE);
pthread_testcancel ();
return temppw;
}
extern "C" struct passwd *
getpwuid (__uid16_t uid)
{
return getpwuid32 (uid16touid32 (uid));
}
extern "C" int
getpwuid_r32 (__uid32_t uid, struct passwd *pwd, char *buffer, size_t bufsize, struct passwd **result)
{
*result = NULL;
if (!pwd || !buffer)
return ERANGE;
struct passwd *temppw = internal_getpwuid (uid, TRUE);
pthread_testcancel ();
if (!temppw)
return 0;
/* check needed buffer size. */
size_t needsize = strlen (temppw->pw_name) + strlen (temppw->pw_dir) +
strlen (temppw->pw_shell) + strlen (temppw->pw_gecos) +
strlen (temppw->pw_passwd) + 5;
if (needsize > bufsize)
return ERANGE;
/* make a copy of temppw */
*result = pwd;
pwd->pw_uid = temppw->pw_uid;
pwd->pw_gid = temppw->pw_gid;
pwd->pw_name = buffer;
pwd->pw_dir = pwd->pw_name + strlen (temppw->pw_name) + 1;
pwd->pw_shell = pwd->pw_dir + strlen (temppw->pw_dir) + 1;
pwd->pw_gecos = pwd->pw_shell + strlen (temppw->pw_shell) + 1;
pwd->pw_passwd = pwd->pw_gecos + strlen (temppw->pw_gecos) + 1;
strcpy (pwd->pw_name, temppw->pw_name);
strcpy (pwd->pw_dir, temppw->pw_dir);
strcpy (pwd->pw_shell, temppw->pw_shell);
strcpy (pwd->pw_gecos, temppw->pw_gecos);
strcpy (pwd->pw_passwd, temppw->pw_passwd);
return 0;
}
extern "C" int
getpwuid_r (__uid16_t uid, struct passwd *pwd, char *buffer, size_t bufsize, struct passwd **result)
{
return getpwuid_r32 (uid16touid32 (uid), pwd, buffer, bufsize, result);
}
extern "C" struct passwd *
getpwnam (const char *name)
{
struct passwd *temppw = internal_getpwnam (name, TRUE);
pthread_testcancel ();
return temppw;
}
/* the max size buffer we can expect to
* use is returned via sysconf with _SC_GETPW_R_SIZE_MAX.
* This may need updating! - Rob Collins April 2001.
*/
extern "C" int
getpwnam_r (const char *nam, struct passwd *pwd, char *buffer, size_t bufsize, struct passwd **result)
{
*result = NULL;
if (!pwd || !buffer || !nam)
return ERANGE;
struct passwd *temppw = internal_getpwnam (nam, TRUE);
pthread_testcancel ();
if (!temppw)
return 0;
/* check needed buffer size. */
size_t needsize = strlen (temppw->pw_name) + strlen (temppw->pw_dir) +
strlen (temppw->pw_shell) + strlen (temppw->pw_gecos) +
strlen (temppw->pw_passwd) + 5;
if (needsize > bufsize)
return ERANGE;
/* make a copy of temppw */
*result = pwd;
pwd->pw_uid = temppw->pw_uid;
pwd->pw_gid = temppw->pw_gid;
pwd->pw_name = buffer;
pwd->pw_dir = pwd->pw_name + strlen (temppw->pw_name) + 1;
pwd->pw_shell = pwd->pw_dir + strlen (temppw->pw_dir) + 1;
pwd->pw_gecos = pwd->pw_shell + strlen (temppw->pw_shell) + 1;
pwd->pw_passwd = pwd->pw_gecos + strlen (temppw->pw_gecos) + 1;
strcpy (pwd->pw_name, temppw->pw_name);
strcpy (pwd->pw_dir, temppw->pw_dir);
strcpy (pwd->pw_shell, temppw->pw_shell);
strcpy (pwd->pw_gecos, temppw->pw_gecos);
strcpy (pwd->pw_passwd, temppw->pw_passwd);
return 0;
}
extern "C" struct passwd *
getpwent (void)
{
if (passwd_state.isinitializing ())
read_etc_passwd ();
if (pw_pos < curr_lines)
return passwd_buf + pw_pos++;
return NULL;
}
extern "C" struct passwd *
getpwduid (__uid16_t)
{
return NULL;
}
extern "C" void
setpwent (void)
{
pw_pos = 0;
}
extern "C" void
endpwent (void)
{
pw_pos = 0;
}
extern "C" int
setpassent ()
{
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.isinitializing ())
read_etc_passwd ();
cygheap_fdget fhstdin (0);
if (fhstdin < 0)
pass[0] = '\0';
else
{
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;
}