minix/lib/libc/gen/getusershell.c

548 lines
12 KiB
C
Raw Normal View History

/* $NetBSD: getusershell.c,v 1.29 2012/03/13 21:13:36 christos Exp $ */
/*-
* Copyright (c) 1999, 2005 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Luke Mewburn.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 1985, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)getusershell.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: getusershell.c,v 1.29 2012/03/13 21:13:36 christos Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include "reentrant.h"
#include <sys/param.h>
#include <sys/file.h>
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <nsswitch.h>
#include <paths.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifdef HESIOD
#include <hesiod.h>
#endif
#ifdef YP
#include <rpc/rpc.h>
#include <rpcsvc/ypclnt.h>
#include <rpcsvc/yp_prot.h>
#endif
#ifdef __weak_alias
__weak_alias(endusershell,_endusershell)
__weak_alias(getusershell,_getusershell)
__weak_alias(setusershell,_setusershell)
#endif
/*
* Local shells should NOT be added here.
* They should be added in /etc/shells.
*/
static const char *const okshells[] = { _PATH_BSHELL, _PATH_CSHELL, NULL };
#ifdef _REENTRANT
static mutex_t __shellmutex = MUTEX_INITIALIZER;
#endif
static char curshell[MAXPATHLEN + 2];
static const char *const *curokshell = okshells;
static int shellsfound = 0;
/*
* files methods
*/
/* state shared between files methods */
struct files_state {
FILE *fp;
};
static struct files_state _files_state;
static int
_files_start(struct files_state *state)
{
_DIAGASSERT(state != NULL);
if (state->fp == NULL) {
state->fp = fopen(_PATH_SHELLS, "re");
if (state->fp == NULL)
return NS_UNAVAIL;
} else {
rewind(state->fp);
}
return NS_SUCCESS;
}
static int
_files_end(struct files_state *state)
{
_DIAGASSERT(state != NULL);
if (state->fp) {
(void) fclose(state->fp);
state->fp = NULL;
}
return NS_SUCCESS;
}
/*ARGSUSED*/
static int
_files_setusershell(void *nsrv, void *nscb, va_list ap)
{
return _files_start(&_files_state);
}
/*ARGSUSED*/
static int
_files_endusershell(void *nsrv, void *nscb, va_list ap)
{
return _files_end(&_files_state);
}
/*ARGSUSED*/
static int
_files_getusershell(void *nsrv, void *nscb, va_list ap)
{
char **retval = va_arg(ap, char **);
char *sp, *cp;
int rv;
_DIAGASSERT(retval != NULL);
*retval = NULL;
if (_files_state.fp == NULL) { /* only start if file not open yet */
rv = _files_start(&_files_state);
if (rv != NS_SUCCESS)
return rv;
}
while (fgets(curshell, (int)sizeof(curshell) - 1, _files_state.fp)
!= NULL) {
sp = cp = curshell;
while (*cp != '#' && *cp != '/' && *cp != '\0')
cp++;
if (*cp == '#' || *cp == '\0')
continue;
sp = cp;
while (!isspace((unsigned char) *cp) && *cp != '#'
&& *cp != '\0')
cp++;
*cp++ = '\0';
*retval = sp;
return NS_SUCCESS;
}
return NS_NOTFOUND;
}
#ifdef HESIOD
/*
* dns methods
*/
/* state shared between dns methods */
struct dns_state {
void *context; /* Hesiod context */
int num; /* shell index, -1 if no more */
};
static struct dns_state _dns_state;
static int
_dns_start(struct dns_state *state)
{
_DIAGASSERT(state != NULL);
state->num = 0;
if (state->context == NULL) { /* setup Hesiod */
if (hesiod_init(&state->context) == -1)
return NS_UNAVAIL;
}
return NS_SUCCESS;
}
static int
_dns_end(struct dns_state *state)
{
_DIAGASSERT(state != NULL);
state->num = 0;
if (state->context) {
hesiod_end(state->context);
state->context = NULL;
}
return NS_SUCCESS;
}
/*ARGSUSED*/
static int
_dns_setusershell(void *nsrv, void *nscb, va_list ap)
{
return _dns_start(&_dns_state);
}
/*ARGSUSED*/
static int
_dns_endusershell(void *nsrv, void *nscb, va_list ap)
{
return _dns_end(&_dns_state);
}
/*ARGSUSED*/
static int
_dns_getusershell(void *nsrv, void *nscb, va_list ap)
{
char **retval = va_arg(ap, char **);
char shellname[] = "shells-NNNNNNNNNN";
char **hp, *ep;
int rv;
_DIAGASSERT(retval != NULL);
*retval = NULL;
if (_dns_state.num == -1) /* exhausted search */
return NS_NOTFOUND;
if (_dns_state.context == NULL) {
/* only start if Hesiod not setup */
rv = _dns_start(&_dns_state);
if (rv != NS_SUCCESS)
return rv;
}
hp = NULL;
rv = NS_NOTFOUND;
/* find shells-NNN */
snprintf(shellname, sizeof(shellname), "shells-%d", _dns_state.num);
_dns_state.num++;
hp = hesiod_resolve(_dns_state.context, shellname, "shells");
if (hp == NULL) {
if (errno == ENOENT)
rv = NS_NOTFOUND;
else
rv = NS_UNAVAIL;
} else {
if ((ep = strchr(hp[0], '\n')) != NULL)
*ep = '\0'; /* clear trailing \n */
/* only use first result */
strlcpy(curshell, hp[0], sizeof(curshell));
*retval = curshell;
rv = NS_SUCCESS;
}
if (hp)
hesiod_free_list(_dns_state.context, hp);
if (rv != NS_SUCCESS)
_dns_state.num = -1; /* any failure halts search */
return rv;
}
#endif /* HESIOD */
#ifdef YP
/*
* nis methods
*/
/* state shared between nis methods */
struct nis_state {
char *domain; /* NIS domain */
int done; /* non-zero if search exhausted */
char *current; /* current first/next match */
int currentlen; /* length of _nis_current */
};
static struct nis_state _nis_state;
static int
_nis_start(struct nis_state *state)
{
_DIAGASSERT(state != NULL);
state->done = 0;
if (state->current) {
free(state->current);
state->current = NULL;
}
if (state->domain == NULL) { /* setup NIS */
switch (yp_get_default_domain(&state->domain)) {
case 0:
break;
case YPERR_RESRC:
return NS_TRYAGAIN;
default:
return NS_UNAVAIL;
}
}
return NS_SUCCESS;
}
static int
_nis_end(struct nis_state *state)
{
_DIAGASSERT(state != NULL);
if (state->domain)
state->domain = NULL;
state->done = 0;
if (state->current)
free(state->current);
state->current = NULL;
return NS_SUCCESS;
}
/*ARGSUSED*/
static int
_nis_setusershell(void *nsrv, void *nscb, va_list ap)
{
return _nis_start(&_nis_state);
}
/*ARGSUSED*/
static int
_nis_endusershell(void *nsrv, void *nscb, va_list ap)
{
return _nis_end(&_nis_state);
}
/*ARGSUSED*/
static int
_nis_getusershell(void *nsrv, void *nscb, va_list ap)
{
char **retval = va_arg(ap, char **);
char *key, *data;
int keylen, datalen, rv, nisr;
_DIAGASSERT(retval != NULL);
*retval = NULL;
if (_nis_state.done) /* exhausted search */
return NS_NOTFOUND;
if (_nis_state.domain == NULL) {
/* only start if NIS not setup */
rv = _nis_start(&_nis_state);
if (rv != NS_SUCCESS)
return rv;
}
key = NULL;
data = NULL;
rv = NS_NOTFOUND;
if (_nis_state.current) { /* already searching */
nisr = yp_next(_nis_state.domain, "shells",
_nis_state.current, _nis_state.currentlen,
&key, &keylen, &data, &datalen);
free(_nis_state.current);
_nis_state.current = NULL;
switch (nisr) {
case 0:
_nis_state.current = key;
_nis_state.currentlen = keylen;
key = NULL;
break;
case YPERR_NOMORE:
rv = NS_NOTFOUND;
goto nisent_out;
default:
rv = NS_UNAVAIL;
goto nisent_out;
}
} else { /* new search */
if (yp_first(_nis_state.domain, "shells",
&_nis_state.current, &_nis_state.currentlen,
&data, &datalen)) {
rv = NS_UNAVAIL;
goto nisent_out;
}
}
data[datalen] = '\0'; /* clear trailing \n */
strlcpy(curshell, data, sizeof(curshell));
*retval = curshell;
rv = NS_SUCCESS;
nisent_out:
if (key)
free(key);
if (data)
free(data);
if (rv != NS_SUCCESS) /* any failure halts search */
_nis_state.done = 1;
return rv;
}
#endif /* YP */
/*
* public functions
*/
void
endusershell(void)
{
static const ns_dtab dtab[] = {
NS_FILES_CB(_files_endusershell, NULL)
NS_DNS_CB(_dns_endusershell, NULL)
NS_NIS_CB(_nis_endusershell, NULL)
NS_NULL_CB
};
mutex_lock(&__shellmutex);
curokshell = okshells; /* reset okshells fallback state */
shellsfound = 0;
/* force all endusershell() methods */
(void) nsdispatch(NULL, dtab, NSDB_SHELLS, "endusershell",
__nsdefaultfiles_forceall);
mutex_unlock(&__shellmutex);
}
__aconst char *
getusershell(void)
{
int rv;
__aconst char *retval;
static const ns_dtab dtab[] = {
NS_FILES_CB(_files_getusershell, NULL)
NS_DNS_CB(_dns_getusershell, NULL)
NS_NIS_CB(_nis_getusershell, NULL)
NS_NULL_CB
};
mutex_lock(&__shellmutex);
retval = NULL;
do {
rv = nsdispatch(NULL, dtab, NSDB_SHELLS, "getusershell",
__nsdefaultsrc, &retval);
/* loop until failure or non-blank result */
} while (rv == NS_SUCCESS && retval[0] == '\0');
if (rv == NS_SUCCESS) {
shellsfound++;
} else if (shellsfound == 0) { /* no shells; fall back to okshells */
if (curokshell != NULL) {
retval = __UNCONST(*curokshell);
curokshell++;
rv = NS_SUCCESS;
}
}
mutex_unlock(&__shellmutex);
return (rv == NS_SUCCESS) ? retval : NULL;
}
void
setusershell(void)
{
static const ns_dtab dtab[] = {
NS_FILES_CB(_files_setusershell, NULL)
NS_DNS_CB(_dns_setusershell, NULL)
NS_NIS_CB(_nis_setusershell, NULL)
NS_NULL_CB
};
mutex_lock(&__shellmutex);
curokshell = okshells; /* reset okshells fallback state */
shellsfound = 0;
/* force all setusershell() methods */
(void) nsdispatch(NULL, dtab, NSDB_SHELLS, "setusershell",
__nsdefaultfiles_forceall);
mutex_unlock(&__shellmutex);
}