newlib/winsup/cygwin/passwd.cc
Corinna Vinschen 50ad198085 Cygwin: Add 'fallthrough' pseudo keyword for switch/case use
This patch has been inspired by the Linux kernel patch

  294f69e662d1 compiler_attributes.h: Add 'fallthrough' pseudo keyword for switch/case use

written by Joe Perches <joe AT perches DOT com> based on an idea from
Dan Carpenter <dan DOT carpenter AT oracle DOT com>.  The following text
is from the original log message:

Reserve the pseudo keyword 'fallthrough' for the ability to convert the
various case block /* fallthrough */ style comments to appear to be an
actual reserved word with the same gcc case block missing fallthrough
warning capability.

All switch/case blocks now should end in one of:

	break;
	fallthrough;
	goto <label>;
	return [expression];
	continue;

In C mode, GCC supports the __fallthrough__ attribute since 7.1,
the same time the warning and the comment parsing were introduced.

Cygwin-only: add an explicit -Wimplicit-fallthrough=5 to the build
flags.
2020-08-05 21:58:22 +02:00

823 lines
19 KiB
C++

/* passwd.cc: getpwnam () and friends
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 <lm.h>
#include <stdlib.h>
#include <stdio.h>
#include "cygerrno.h"
#include "security.h"
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "pinfo.h"
#include "cygheap.h"
#include "shared_info.h"
#include "miscfuncs.h"
#include "ldap.h"
#include "tls_pbuf.h"
/* Parse /etc/passwd line into passwd structure. */
bool
pwdgrp::parse_passwd ()
{
pg_pwd &res = passwd ()[curr_lines];
res.p.pw_name = next_str (':');
res.p.pw_passwd = next_str (':');
if (!next_num (res.p.pw_uid))
return false;
if (!next_num (res.p.pw_gid))
return false;
res.p.pw_comment = NULL;
res.p.pw_gecos = next_str (':');
res.p.pw_dir = next_str (':');
res.p.pw_shell = next_str (':');
cygsid csid;
if (csid.getfrompw_gecos (&res.p))
RtlCopySid (SECURITY_MAX_SID_SIZE, res.sid, csid);
/* lptr points to the \0 after pw_shell. Increment by one to get the correct
required buffer len in getpw_cp. */
res.len = lptr - res.p.pw_name + 1;
return true;
}
void
pwdgrp::init_pwd ()
{
pwdgrp_buf_elem_size = sizeof (pg_pwd);
parse = &pwdgrp::parse_passwd;
}
struct passwd *
pwdgrp::find_user (cygpsid &sid)
{
for (ULONG i = 0; i < curr_lines; i++)
if (sid == passwd ()[i].sid)
return &passwd ()[i].p;
return NULL;
}
struct passwd *
pwdgrp::find_user (const char *name)
{
for (ULONG i = 0; i < curr_lines; i++)
/* on Windows NT user names are case-insensitive */
if (strcasematch (name, passwd ()[i].p.pw_name))
return &passwd ()[i].p;
return NULL;
}
struct passwd *
pwdgrp::find_user (uid_t uid)
{
for (ULONG i = 0; i < curr_lines; i++)
if (uid == passwd ()[i].p.pw_uid)
return &passwd ()[i].p;
return NULL;
}
struct passwd *
internal_getpwsid (cygpsid &sid, cyg_ldap *pldap)
{
struct passwd *ret;
cygheap->pg.nss_init ();
/* Check caches first. */
if (cygheap->pg.nss_cygserver_caching ()
&& (ret = cygheap->pg.pwd_cache.cygserver.find_user (sid)))
return ret;
if (cygheap->pg.nss_pwd_files ()
&& (ret = cygheap->pg.pwd_cache.file.find_user (sid)))
return ret;
if (cygheap->pg.nss_pwd_db ()
&& (ret = cygheap->pg.pwd_cache.win.find_user (sid)))
return ret;
/* Ask sources afterwards. */
if (cygheap->pg.nss_cygserver_caching ()
&& (ret = cygheap->pg.pwd_cache.cygserver.add_user_from_cygserver (sid)))
return ret;
if (cygheap->pg.nss_pwd_files ())
{
cygheap->pg.pwd_cache.file.check_file ();
if ((ret = cygheap->pg.pwd_cache.file.add_user_from_file (sid)))
return ret;
}
if (cygheap->pg.nss_pwd_db ())
return cygheap->pg.pwd_cache.win.add_user_from_windows (sid, pldap);
return NULL;
}
/* This function gets only called from mkpasswd via cygwin_internal. */
struct passwd *
internal_getpwsid_from_db (cygpsid &sid)
{
cygheap->pg.nss_init ();
return cygheap->pg.pwd_cache.win.add_user_from_windows (sid);
}
struct passwd *
internal_getpwnam (const char *name, cyg_ldap *pldap)
{
struct passwd *ret;
cygheap->pg.nss_init ();
/* Check caches first. */
if (cygheap->pg.nss_cygserver_caching ()
&& (ret = cygheap->pg.pwd_cache.cygserver.find_user (name)))
return ret;
if (cygheap->pg.nss_pwd_files ()
&& (ret = cygheap->pg.pwd_cache.file.find_user (name)))
return ret;
if (cygheap->pg.nss_pwd_db ()
&& (ret = cygheap->pg.pwd_cache.win.find_user (name)))
return ret;
/* Ask sources afterwards. */
if (cygheap->pg.nss_cygserver_caching ()
&& (ret = cygheap->pg.pwd_cache.cygserver.add_user_from_cygserver (name)))
return ret;
if (cygheap->pg.nss_pwd_files ())
{
cygheap->pg.pwd_cache.file.check_file ();
if ((ret = cygheap->pg.pwd_cache.file.add_user_from_file (name)))
return ret;
}
if (cygheap->pg.nss_pwd_db ())
return cygheap->pg.pwd_cache.win.add_user_from_windows (name, pldap);
return NULL;
}
struct passwd *
internal_getpwuid (uid_t uid, cyg_ldap *pldap)
{
struct passwd *ret;
cygheap->pg.nss_init ();
/* Check caches first. */
if (cygheap->pg.nss_cygserver_caching ()
&& (ret = cygheap->pg.pwd_cache.cygserver.find_user (uid)))
return ret;
if (cygheap->pg.nss_pwd_files ()
&& (ret = cygheap->pg.pwd_cache.file.find_user (uid)))
return ret;
if (cygheap->pg.nss_pwd_db ()
&& (ret = cygheap->pg.pwd_cache.win.find_user (uid)))
return ret;
/* Ask sources afterwards. */
if (cygheap->pg.nss_cygserver_caching ()
&& (ret = cygheap->pg.pwd_cache.cygserver.add_user_from_cygserver (uid)))
return ret;
if (cygheap->pg.nss_pwd_files ())
{
cygheap->pg.pwd_cache.file.check_file ();
if ((ret = cygheap->pg.pwd_cache.file.add_user_from_file (uid)))
return ret;
}
if (cygheap->pg.nss_pwd_db () || uid == ILLEGAL_UID)
return cygheap->pg.pwd_cache.win.add_user_from_windows (uid, pldap);
return NULL;
}
/* getpwuid/getpwnam are not reentrant. */
static struct {
struct passwd p;
char *buf;
size_t bufsiz;
} app_pw;
static struct passwd *
getpw_cp (struct passwd *temppw)
{
if (!temppw)
return NULL;
pg_pwd *pw = (pg_pwd *) temppw;
if (app_pw.bufsiz < pw->len)
{
char *newbuf = (char *) realloc (app_pw.buf, pw->len);
if (!newbuf)
{
set_errno (ENOMEM);
return NULL;
}
app_pw.buf = newbuf;
app_pw.bufsiz = pw->len;
}
memcpy (app_pw.buf, pw->p.pw_name, pw->len);
memcpy (&app_pw.p, &pw->p, sizeof pw->p);
ptrdiff_t diff = app_pw.buf - pw->p.pw_name;
app_pw.p.pw_name += diff;
app_pw.p.pw_passwd += diff;
app_pw.p.pw_gecos += diff;
app_pw.p.pw_dir += diff;
app_pw.p.pw_shell += diff;
return &app_pw.p;
}
extern "C" struct passwd *
getpwuid32 (uid_t uid)
{
struct passwd *temppw = internal_getpwuid (uid);
pthread_testcancel ();
return getpw_cp (temppw);
}
#ifdef __i386__
extern "C" struct passwd *
getpwuid (__uid16_t uid)
{
return getpwuid32 (uid16touid32 (uid));
}
#else
EXPORT_ALIAS (getpwuid32, getpwuid)
#endif
extern "C" int
getpwuid_r32 (uid_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);
pthread_testcancel ();
if (!temppw)
return 0;
/* check needed buffer size. */
size_t needsize = strlen (temppw->pw_name) + strlen (temppw->pw_passwd)
+ strlen (temppw->pw_gecos) + strlen (temppw->pw_dir)
+ strlen (temppw->pw_shell) + 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;
buffer = stpcpy (pwd->pw_name = buffer, temppw->pw_name);
buffer = stpcpy (pwd->pw_passwd = buffer + 1, temppw->pw_passwd);
buffer = stpcpy (pwd->pw_gecos = buffer + 1, temppw->pw_gecos);
buffer = stpcpy (pwd->pw_dir = buffer + 1, temppw->pw_dir);
stpcpy (pwd->pw_shell = buffer + 1, temppw->pw_shell);
pwd->pw_comment = NULL;
return 0;
}
#ifdef __x86_64__
EXPORT_ALIAS (getpwuid_r32, getpwuid_r)
#else
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);
}
#endif
extern "C" struct passwd *
getpwnam (const char *name)
{
struct passwd *temppw = internal_getpwnam (name);
pthread_testcancel ();
return getpw_cp (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);
pthread_testcancel ();
if (!temppw)
return 0;
/* check needed buffer size. */
size_t needsize = strlen (temppw->pw_name) + strlen (temppw->pw_passwd)
+ strlen (temppw->pw_gecos) + strlen (temppw->pw_dir)
+ strlen (temppw->pw_shell) + 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;
buffer = stpcpy (pwd->pw_name = buffer, temppw->pw_name);
buffer = stpcpy (pwd->pw_passwd = buffer + 1, temppw->pw_passwd);
buffer = stpcpy (pwd->pw_gecos = buffer + 1, temppw->pw_gecos);
buffer = stpcpy (pwd->pw_dir = buffer + 1, temppw->pw_dir);
stpcpy (pwd->pw_shell = buffer + 1, temppw->pw_shell);
pwd->pw_comment = NULL;
return 0;
}
/* getpwent functions are not reentrant. */
static pw_ent pwent;
void
pg_ent::clear_cache ()
{
if (pg.curr_lines)
{
if (state > from_file)
cfree (group ? grp.g.gr_name : pwd.p.pw_name);
pg.curr_lines = 0;
}
}
void
pg_ent::setent (bool _group, int _enums, PCWSTR _enum_tdoms)
{
cygheap->dom.init ();
endent (_group);
if (!_enums && !_enum_tdoms)
{
/* This is the default, when called from the usual setpwent/setgrent
functions. */
enums = cygheap->pg.nss_db_enums ();
enum_tdoms = cygheap->pg.nss_db_enum_tdoms ();
if (_group)
{
from_files = cygheap->pg.nss_grp_files ();
from_db = cygheap->pg.nss_grp_db ();
}
else
{
from_files = cygheap->pg.nss_pwd_files ();
from_db = cygheap->pg.nss_pwd_db ();
}
}
else
{
/* This case is when called from mkpasswd/mkgroup via cygwin_internal. */
enums = _enums;
enum_tdoms = _enum_tdoms;
from_files = false;
from_db = true;
}
state = from_cache;
}
void *
pg_ent::getent (void)
{
void *entry;
switch (state)
{
case rewound:
state = from_cache;
fallthrough;
case from_cache:
if (nss_db_enum_caches ()
&& (entry = enumerate_caches ()))
return entry;
state = from_file;
fallthrough;
case from_file:
if (from_files
&& nss_db_enum_files ()
&& (entry = enumerate_file ()))
return entry;
state = from_builtin;
fallthrough;
case from_builtin:
if (from_db
&& nss_db_enum_builtin ()
&& (entry = enumerate_builtin ()))
return entry;
state = from_local;
fallthrough;
case from_local:
if (from_db
&& nss_db_enum_local ()
&& (!cygheap->dom.member_machine ()
|| !nss_db_enum_primary ())
&& (entry = enumerate_local ()))
return entry;
state = from_sam;
fallthrough;
case from_sam:
if (from_db
&& nss_db_enum_local ()
/* Domain controller? If so, sam and ad are one and the same
and "local ad" would list all domain accounts twice without
this test. */
&& (cygheap->dom.account_flat_name ()[0] != L'@'
|| !nss_db_enum_primary ())
&& (entry = enumerate_sam ()))
return entry;
state = from_ad;
fallthrough;
case from_ad:
if (cygheap->dom.member_machine ()
&& from_db
&& (entry = enumerate_ad ()))
return entry;
state = finished;
fallthrough;
case finished:
break;
}
return NULL;
}
void
pg_ent::endent (bool _group)
{
if (buf)
{
if (state == from_file)
free (buf);
else if (state == from_local || state == from_sam)
NetApiBufferFree (buf);
buf = NULL;
}
if (!pg.curr_lines)
{
if ((group = _group))
{
pg.init_grp ();
pg.pwdgrp_buf = (void *) &grp;
}
else
{
pg.init_pwd ();
pg.pwdgrp_buf = (void *) &pwd;
}
pg.max_lines = 1;
}
else
clear_cache ();
cldap.close ();
rl.close ();
cnt = max = resume = 0;
enums = 0;
enum_tdoms = NULL;
state = rewound;
}
void *
pg_ent::enumerate_file ()
{
void *entry;
if (!cnt)
{
pwdgrp &prf = group ? cygheap->pg.grp_cache.file
: cygheap->pg.pwd_cache.file;
if (prf.check_file ())
{
if (!buf)
buf = (char *) malloc (NT_MAX_PATH);
if (buf
&& !rl.init (prf.file_attr (), buf, NT_MAX_PATH))
{
free (buf);
buf = NULL;
}
}
}
++cnt;
if ((entry = pg.add_account_post_fetch (rl.gets (), false)))
return entry;
rl.close ();
free (buf);
buf = NULL;
cnt = max = resume = 0;
return NULL;
}
void *
pg_ent::enumerate_builtin ()
{
static cygpsid *pwd_builtins[] = {
&well_known_system_sid,
&well_known_local_service_sid,
&well_known_network_service_sid,
&well_known_admins_sid,
&trusted_installer_sid,
NULL
};
static cygpsid *grp_builtins[] = {
&well_known_system_sid,
&trusted_installer_sid,
NULL
};
cygpsid **builtins = group ? grp_builtins : pwd_builtins;
if (!builtins[cnt])
{
cnt = max = resume = 0;
return NULL;
}
cygsid sid (*builtins[cnt++]);
fetch_user_arg_t arg;
arg.type = SID_arg;
arg.sid = &sid;
char *line = pg.fetch_account_from_windows (arg);
return pg.add_account_post_fetch (line, false);
}
void *
pg_ent::enumerate_sam ()
{
while (true)
{
if (!cnt)
{
DWORD total;
NET_API_STATUS ret;
if (buf)
{
NetApiBufferFree (buf);
buf = NULL;
}
if (resume == ULONG_MAX)
ret = ERROR_NO_MORE_ITEMS;
else if (group)
ret = NetGroupEnum (NULL, 2, (PBYTE *) &buf, MAX_PREFERRED_LENGTH,
&max, &total, &resume);
else
ret = NetUserEnum (NULL, 20, FILTER_NORMAL_ACCOUNT, (PBYTE *) &buf,
MAX_PREFERRED_LENGTH, &max, &total,
(PDWORD) &resume);
if (ret == NERR_Success)
resume = ULONG_MAX;
else if (ret != ERROR_MORE_DATA)
{
cnt = max = resume = 0;
return NULL;
}
}
while (cnt < max)
{
cygsid sid (cygheap->dom.account_sid ());
sid_sub_auth (sid, sid_sub_auth_count (sid)) =
group ? ((PGROUP_INFO_2) buf)[cnt].grpi2_group_id
: ((PUSER_INFO_20) buf)[cnt].usri20_user_id;
++cnt;
++sid_sub_auth_count (sid);
fetch_user_arg_t arg;
arg.type = SID_arg;
arg.sid = &sid;
char *line = pg.fetch_account_from_windows (arg);
if (line)
return pg.add_account_post_fetch (line, false);
}
cnt = 0;
}
}
void *
pg_ent::enumerate_ad ()
{
while (true)
{
if (!cnt)
{
PDS_DOMAIN_TRUSTSW td;
if (!resume)
{
++resume;
if (!nss_db_enum_primary ()
|| cldap.enumerate_ad_accounts (NULL, group) != NO_ERROR)
continue;
RtlInitUnicodeString (&dom, cygheap->dom.primary_flat_name ());
}
else if ((td = cygheap->dom.trusted_domain (resume - 1)))
{
++resume;
/* Ignore primary domain in list of trusted domains only if all
trusted domains are enumerated anyway. This handles an
annoying backward compatibility problem in mkpasswd/mkgroup.
Without this test, `mkpasswd -d PRIMARY_DOMAIN' wouldn't
work as expected. */
if (((enums & ENUM_TDOMS_ALL) && td->Flags & DS_DOMAIN_PRIMARY)
|| !td->DomainSid
|| (!nss_db_enum_tdom (td->NetbiosDomainName)
&& !nss_db_enum_tdom (td->DnsDomainName))
|| cldap.enumerate_ad_accounts (td->DnsDomainName, group)
!= NO_ERROR)
continue;
RtlInitUnicodeString (&dom, td->NetbiosDomainName);
}
else
{
cldap.close ();
return NULL;
}
}
++cnt;
cygsid sid;
int ret = cldap.next_account (sid);
if (ret == NO_ERROR)
{
fetch_acc_t full;
fetch_user_arg_t arg;
UNICODE_STRING name;
arg.type = FULL_acc_arg;
arg.full_acc = &full;
full.sid = sid;
RtlInitUnicodeString (&name,
cldap.get_string_attribute (L"sAMAccountName"));
full.name = &name;
full.dom = &dom;
if (sid_sub_auth (sid, 0) == SECURITY_BUILTIN_DOMAIN_RID)
full.acc_type = SidTypeAlias;
else
full.acc_type = group ? SidTypeGroup : SidTypeUser;
char *line = pg.fetch_account_from_windows (arg, &cldap);
if (line)
return pg.add_account_post_fetch (line, false);
ret = EIO;
}
if (ret != ENMFILE)
{
cldap.close ();
set_errno (ret);
return NULL;
}
cnt = 0;
}
}
void *
pw_ent::enumerate_caches ()
{
switch (max)
{
case 0:
if (cygheap->pg.nss_cygserver_caching ())
{
pwdgrp &prc = cygheap->pg.pwd_cache.cygserver;
if (cnt < prc.cached_users ())
return &prc.passwd ()[cnt++].p;
}
cnt = 0;
max = 1;
fallthrough;
case 1:
if (from_files)
{
pwdgrp &prf = cygheap->pg.pwd_cache.file;
prf.check_file ();
if (cnt < prf.cached_users ())
return &prf.passwd ()[cnt++].p;
}
cnt = 0;
max = 2;
fallthrough;
default:
if (from_db)
{
pwdgrp &prw = cygheap->pg.pwd_cache.win;
if (cnt < prw.cached_users ())
return &prw.passwd ()[cnt++].p;
}
break;
}
cnt = max = 0;
return NULL;
}
void *
pw_ent::enumerate_local ()
{
return NULL;
}
struct passwd *
pw_ent::getpwent (void)
{
if (state == rewound)
setent (false);
else
clear_cache ();
return (struct passwd *) getent ();
}
extern "C" void
setpwent ()
{
pwent.setpwent ();
}
extern "C" struct passwd *
getpwent (void)
{
return pwent.getpwent ();
}
extern "C" void
endpwent (void)
{
pwent.endpwent ();
}
/* *_filtered functions are called from mkpasswd */
void *
setpwent_filtered (int enums, PCWSTR enum_tdoms)
{
pw_ent *pw = new pw_ent;
if (pw)
pw->setpwent (enums, enum_tdoms);
return (void *) pw;
}
void *
getpwent_filtered (void *pw)
{
return (void *) ((pw_ent *) pw)->getpwent ();
}
void
endpwent_filtered (void *pw)
{
((pw_ent *) pw)->endpwent ();
}
#ifdef __i386__
extern "C" struct passwd *
getpwduid (__uid16_t)
{
return NULL;
}
#endif
extern "C" int
setpassent (int)
{
return 0;
}
static void
_getpass_close_fd (void *arg)
{
if (arg)
fclose ((FILE *) arg);
}
extern "C" char *
getpass (const char * prompt)
{
char *pass = _my_tls.locals.pass;
struct termios ti, newti;
bool tc_set = false;
/* Try to use controlling tty in the first place. Use stdin and stderr
only as fallback. */
FILE *in = stdin, *err = stderr;
FILE *tty = fopen ("/dev/tty", "w+b");
pthread_cleanup_push (_getpass_close_fd, tty);
if (tty)
{
/* Set close-on-exec for obvious reasons. */
fcntl (fileno (tty), F_SETFD, fcntl (fileno (tty), F_GETFD) | FD_CLOEXEC);
in = err = tty;
}
/* Make sure to notice if stdin is closed. */
if (fileno (in) >= 0)
{
flockfile (in);
/* Change tty attributes if possible. */
if (!tcgetattr (fileno (in), &ti))
{
newti = ti;
newti.c_lflag &= ~(ECHO | ISIG); /* No echo, no signal handling. */
if (!tcsetattr (fileno (in), TCSANOW, &newti))
tc_set = true;
}
fputs (prompt, err);
fflush (err);
fgets (pass, _PASSWORD_LEN, in);
fprintf (err, "\n");
if (tc_set)
tcsetattr (fileno (in), TCSANOW, &ti);
funlockfile (in);
char *crlf = strpbrk (pass, "\r\n");
if (crlf)
*crlf = '\0';
}
pthread_cleanup_pop (1);
return pass;
}