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/*
* SPDX-License-Identifier: ISC
*
* Copyright (c) 2007-2015 Todd C. Miller <Todd.Miller@sudo.ws>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* This is an open source non-commercial project. Dear PVS-Studio, please check it.
* PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif /* HAVE_STRINGS_H */
#include <ctype.h>
#include <sudoers.h>
extern struct sudo_nss sudo_nss_file;
#ifdef HAVE_LDAP
extern struct sudo_nss sudo_nss_ldap;
#endif
#ifdef HAVE_SSSD
extern struct sudo_nss sudo_nss_sss;
#endif
/* Make sure we have not already inserted the nss entry. */
#define SUDO_NSS_CHECK_UNUSED(nss, tag) \
if (nss.entries.tqe_next != NULL || nss.entries.tqe_prev != NULL) { \
sudo_warnx("internal error: nsswitch entry \"%s\" already in use", \
tag); \
continue; \
}
#if (defined(HAVE_LDAP) || defined(HAVE_SSSD)) && defined(_PATH_NSSWITCH_CONF)
/*
* Read in /etc/nsswitch.conf
* Returns a tail queue of matches.
*/
struct sudo_nss_list *
sudo_read_nss(void)
{
FILE *fp;
char *line = NULL;
size_t linesize = 0;
#ifdef HAVE_SSSD
bool saw_sss = false;
#endif
#ifdef HAVE_LDAP
bool saw_ldap = false;
#endif
bool saw_files = false;
bool got_match = false;
static struct sudo_nss_list snl = TAILQ_HEAD_INITIALIZER(snl);
debug_decl(sudo_read_nss, SUDOERS_DEBUG_NSS);
if ((fp = fopen(_PATH_NSSWITCH_CONF, "r")) == NULL)
goto nomatch;
while (sudo_parseln(&line, &linesize, NULL, fp, 0) != -1) {
char *cp, *last;
/* Skip blank or comment lines */
if (*line == '\0')
continue;
/* Look for a line starting with "sudoers:" */
if (strncasecmp(line, "sudoers:", 8) != 0)
continue;
/* Parse line */
for ((cp = strtok_r(line + 8, " \t", &last)); cp != NULL; (cp = strtok_r(NULL, " \t", &last))) {
if (strcasecmp(cp, "files") == 0 && !saw_files) {
SUDO_NSS_CHECK_UNUSED(sudo_nss_file, "files");
TAILQ_INSERT_TAIL(&snl, &sudo_nss_file, entries);
got_match = saw_files = true;
#ifdef HAVE_LDAP
} else if (strcasecmp(cp, "ldap") == 0 && !saw_ldap) {
SUDO_NSS_CHECK_UNUSED(sudo_nss_ldap, "ldap");
TAILQ_INSERT_TAIL(&snl, &sudo_nss_ldap, entries);
got_match = saw_ldap = true;
#endif
#ifdef HAVE_SSSD
} else if (strcasecmp(cp, "sss") == 0 && !saw_sss) {
SUDO_NSS_CHECK_UNUSED(sudo_nss_sss, "sss");
TAILQ_INSERT_TAIL(&snl, &sudo_nss_sss, entries);
got_match = saw_sss = true;
#endif
} else if (strcasecmp(cp, "[NOTFOUND=return]") == 0 && got_match) {
/* NOTFOUND affects the most recent entry */
TAILQ_LAST(&snl, sudo_nss_list)->ret_if_notfound = true;
got_match = false;
} else if (strcasecmp(cp, "[SUCCESS=return]") == 0 && got_match) {
/* SUCCESS affects the most recent entry */
TAILQ_LAST(&snl, sudo_nss_list)->ret_if_found = true;
got_match = false;
} else
got_match = false;
}
/* Only parse the first "sudoers:" line */
break;
}
free(line);
fclose(fp);
nomatch:
/* Default to files only if no matches */
if (TAILQ_EMPTY(&snl))
TAILQ_INSERT_TAIL(&snl, &sudo_nss_file, entries);
debug_return_ptr(&snl);
}
#else /* (HAVE_LDAP || HAVE_SSSD) && _PATH_NSSWITCH_CONF */
# if (defined(HAVE_LDAP) || defined(HAVE_SSSD)) && defined(_PATH_NETSVC_CONF)
/*
* Read in /etc/netsvc.conf (like nsswitch.conf on AIX)
* Returns a tail queue of matches.
*/
struct sudo_nss_list *
sudo_read_nss(void)
{
FILE *fp;
char *cp, *ep, *last, *line = NULL;
size_t linesize = 0;
#ifdef HAVE_SSSD
bool saw_sss = false;
#endif
bool saw_files = false;
bool saw_ldap = false;
bool got_match = false;
static struct sudo_nss_list snl = TAILQ_HEAD_INITIALIZER(snl);
debug_decl(sudo_read_nss, SUDOERS_DEBUG_NSS);
if ((fp = fopen(_PATH_NETSVC_CONF, "r")) == NULL)
goto nomatch;
while (sudo_parseln(&line, &linesize, NULL, fp, 0) != -1) {
/* Skip blank or comment lines */
if (*(cp = line) == '\0')
continue;
/* Look for a line starting with "sudoers = " */
if (strncasecmp(cp, "sudoers", 7) != 0)
continue;
cp += 7;
while (isspace((unsigned char)*cp))
cp++;
if (*cp++ != '=')
continue;
/* Parse line */
for ((cp = strtok_r(cp, ",", &last)); cp != NULL; (cp = strtok_r(NULL, ",", &last))) {
/* Trim leading whitespace. */
while (isspace((unsigned char)*cp))
cp++;
if (!saw_files && strncasecmp(cp, "files", 5) == 0 &&
(isspace((unsigned char)cp[5]) || cp[5] == '\0')) {
TAILQ_INSERT_TAIL(&snl, &sudo_nss_file, entries);
got_match = saw_files = true;
ep = &cp[5];
#ifdef HAVE_LDAP
} else if (!saw_ldap && strncasecmp(cp, "ldap", 4) == 0 &&
(isspace((unsigned char)cp[4]) || cp[4] == '\0')) {
TAILQ_INSERT_TAIL(&snl, &sudo_nss_ldap, entries);
got_match = saw_ldap = true;
ep = &cp[4];
#endif
#ifdef HAVE_SSSD
} else if (!saw_sss && strncasecmp(cp, "sss", 3) == 0 &&
(isspace((unsigned char)cp[3]) || cp[3] == '\0')) {
TAILQ_INSERT_TAIL(&snl, &sudo_nss_sss, entries);
got_match = saw_sss = true;
ep = &cp[3];
#endif
} else {
got_match = false;
}
/* check for = auth qualifier */
if (got_match && *ep) {
cp = ep;
while (isspace((unsigned char)*cp) || *cp == '=')
cp++;
if (strncasecmp(cp, "auth", 4) == 0 &&
(isspace((unsigned char)cp[4]) || cp[4] == '\0')) {
TAILQ_LAST(&snl, sudo_nss_list)->ret_if_found = true;
}
}
}
/* Only parse the first "sudoers" line */
break;
}
fclose(fp);
nomatch:
/* Default to files only if no matches */
if (TAILQ_EMPTY(&snl))
TAILQ_INSERT_TAIL(&snl, &sudo_nss_file, entries);
debug_return_ptr(&snl);
}
# else /* !_PATH_NETSVC_CONF && !_PATH_NSSWITCH_CONF */
/*
* Non-nsswitch.conf version with hard-coded order.
*/
struct sudo_nss_list *
sudo_read_nss(void)
{
static struct sudo_nss_list snl = TAILQ_HEAD_INITIALIZER(snl);
debug_decl(sudo_read_nss, SUDOERS_DEBUG_NSS);
# ifdef HAVE_SSSD
TAILQ_INSERT_TAIL(&snl, &sudo_nss_sss, entries);
# endif
# ifdef HAVE_LDAP
TAILQ_INSERT_TAIL(&snl, &sudo_nss_ldap, entries);
# endif
TAILQ_INSERT_TAIL(&snl, &sudo_nss_file, entries);
debug_return_ptr(&snl);
}
# endif /* !HAVE_LDAP || !_PATH_NETSVC_CONF */
#endif /* HAVE_LDAP && _PATH_NSSWITCH_CONF */
bool
sudo_nss_can_continue(const struct sudo_nss *nss, int match)
{
debug_decl(sudo_nss_should_continue, SUDOERS_DEBUG_NSS);
/* Handle [NOTFOUND=return] */
if (nss->ret_if_notfound && match == UNSPEC)
debug_return_bool(false);
/* Handle [SUCCESS=return] */
if (nss->ret_if_found && match != UNSPEC)
debug_return_bool(false);
debug_return_bool(true);
}
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