/*      $OpenBSD: getgrent.c,v 1.51 2026/03/10 00:06:39 deraadt Exp $ */
/*
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 * Portions Copyright (c) 1994, Jason Downs. 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/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <unistd.h>
#include <fcntl.h>
#include <grp.h>
#include <errno.h>
#ifdef YP
#include <rpc/rpc.h>
#include <rpcsvc/yp.h>
#include <rpcsvc/ypclnt.h>
#include "ypinternal.h"
#include "ypexclude.h"
#endif
#include "thread_private.h"

/* This global storage is locked for the non-rentrant functions */
_THREAD_PRIVATE_KEY(gr_storage);
static struct group_storage {
#define MAXGRP          200
        char *members[MAXGRP];
#define MAXLINELENGTH   1024
        char line[MAXLINELENGTH];
} gr_storage;
#define GETGR_R_SIZE_MAX        _GR_BUF_LEN

/* File pointers are locked with the 'gr' mutex */
_THREAD_PRIVATE_KEY(gr);
static FILE *_gr_fp;
static struct group _gr_group;
static int _gr_stayopen;
static int grscan(int, gid_t, const char *, struct group *, struct group_storage *,
        int *);
static int start_gr(void);
static void endgrent_basic(void);

static struct group *getgrnam_gs(const char *, struct group *,
        struct group_storage *);
static struct group *getgrgid_gs(gid_t, struct group *,
        struct group_storage *);

#ifdef YP
static struct _ypexclude *__ypexhead = NULL;
static int      __ypmode = 0;
static char     *__ypcurrent, *__ypdomain;
static int      __ypcurrentlen;
#endif

struct group *
_getgrent_yp(int *foundyp)
{
        struct group *p_gr = (struct group*)_THREAD_PRIVATE(gr, _gr_group, NULL);
        struct group_storage *gs = (struct group_storage *)_THREAD_PRIVATE(gr_storage,
            gr_storage, NULL);

        _THREAD_PRIVATE_MUTEX_LOCK(gr);
        if ((!_gr_fp && !start_gr()) || !grscan(0, 0, NULL, p_gr, gs, foundyp))
                p_gr = NULL;
        _THREAD_PRIVATE_MUTEX_UNLOCK(gr);
        return (p_gr);
}

struct group *
getgrent(void)
{
        return (_getgrent_yp(NULL));
}

static struct group *
getgrnam_gs(const char *name, struct group *p_gr, struct group_storage *gs)
{
        int rval;

        _THREAD_PRIVATE_MUTEX_LOCK(gr);
        if (!start_gr())
                rval = 0;
        else {
                rval = grscan(1, 0, name, p_gr, gs, NULL);
                if (!_gr_stayopen)
                        endgrent_basic();
        }
        _THREAD_PRIVATE_MUTEX_UNLOCK(gr);
        return(rval ? p_gr : NULL);
}

struct group *
getgrnam(const char *name)
{
        struct group *p_gr = (struct group*)_THREAD_PRIVATE(gr,_gr_group,NULL);
        struct group_storage *gs = (struct group_storage *)_THREAD_PRIVATE(gr_storage,
            gr_storage, NULL);

        return getgrnam_gs(name, p_gr, gs);
}

int
getgrnam_r(const char *name, struct group *grp, char *buffer,
        size_t bufsize, struct group **result)
{
        int errnosave;
        int ret;

        if (bufsize < GETGR_R_SIZE_MAX)
                return ERANGE;
        errnosave = errno;
        errno = 0;
        *result = getgrnam_gs(name, grp, (struct group_storage *)buffer);
        if (*result == NULL)
                ret = errno;
        else
                ret = 0;
        errno = errnosave;
        return ret;
}
DEF_WEAK(getgrnam_r);

static struct group *
getgrgid_gs(gid_t gid, struct group *p_gr, struct group_storage *gs)
{
        int rval;

        _THREAD_PRIVATE_MUTEX_LOCK(gr);
        if (!start_gr())
                rval = 0;
        else {
                rval = grscan(1, gid, NULL, p_gr, gs, NULL);
                if (!_gr_stayopen)
                        endgrent_basic();
        }
        _THREAD_PRIVATE_MUTEX_UNLOCK(gr);
        return(rval ? p_gr : NULL);
}

struct group *
getgrgid(gid_t gid)
{
        struct group *p_gr = (struct group*)_THREAD_PRIVATE(gr, _gr_group, NULL);
        struct group_storage *gs = (struct group_storage *)_THREAD_PRIVATE(gr_storage,
            gr_storage, NULL);

        return getgrgid_gs(gid, p_gr, gs);
}

int
getgrgid_r(gid_t gid, struct group *grp, char *buffer, size_t bufsize,
        struct group **result)
{
        int errnosave;
        int ret;

        if (bufsize < GETGR_R_SIZE_MAX)
                return ERANGE;
        errnosave = errno;
        errno = 0;
        *result = getgrgid_gs(gid, grp, (struct group_storage *)buffer);
        if (*result == NULL)
                ret = errno;
        else
                ret = 0;
        errno = errnosave;
        return ret;
}
DEF_WEAK(getgrgid_r);

static int
start_gr(void)
{
        int fd;

        if (_gr_fp) {
                rewind(_gr_fp);
#ifdef YP
                __ypmode = 0;
                free(__ypcurrent);
                __ypcurrent = NULL;
                if (__ypexhead)
                        __ypexclude_free(&__ypexhead);
                __ypexhead = NULL;
#endif
                return(1);
        }

        fd = __pledge_open(_PATH_GROUP, O_RDONLY|O_CLOEXEC);
        if (fd == -1)
                return 0;
        if ((_gr_fp = fdopen(fd, "r")) == NULL)
                close(fd);
        return (_gr_fp  ? 1 : 0);
}

void
setgrent(void)
{
        int saved_errno;

        saved_errno = errno;
        setgroupent(0);
        errno = saved_errno;
}
DEF_WEAK(setgrent);

int
setgroupent(int stayopen)
{
        int retval;

        _THREAD_PRIVATE_MUTEX_LOCK(gr);
        if (!start_gr())
                retval = 0;
        else {
                _gr_stayopen = stayopen;
                retval = 1;
        }
        _THREAD_PRIVATE_MUTEX_UNLOCK(gr);
        return (retval);
}
DEF_WEAK(setgroupent);

static
void
endgrent_basic(void)
{
        int saved_errno;

        if (_gr_fp) {
                saved_errno = errno;
                fclose(_gr_fp);
                _gr_fp = NULL;
#ifdef YP
                __ypmode = 0;
                free(__ypcurrent);
                __ypcurrent = NULL;
                if (__ypexhead)
                        __ypexclude_free(&__ypexhead);
                __ypexhead = NULL;
#endif
                errno = saved_errno;
        }
}

void
endgrent(void)
{
        _THREAD_PRIVATE_MUTEX_LOCK(gr);
        endgrent_basic();
        _THREAD_PRIVATE_MUTEX_UNLOCK(gr);
}
DEF_WEAK(endgrent);

static int
grscan(int search, gid_t gid, const char *name, struct group *p_gr,
    struct group_storage *gs, int *foundyp)
{
        char *cp, **m;
        char *bp, *endp;
        u_long ul;
#ifdef YP
        char *key, *data;
        int keylen, datalen;
        int r;
#endif
        char **members;
        char *line;
        int saved_errno;

        if (gs == NULL)
                return 0;
        members = gs->members;
        line = gs->line;
        saved_errno = errno;

        for (;;) {
#ifdef YP
                if (__ypmode) {
                        if (__ypcurrent) {
                                r = yp_next(__ypdomain, "group.byname",
                                    __ypcurrent, __ypcurrentlen,
                                    &key, &keylen, &data, &datalen);
                                free(__ypcurrent);
                                __ypcurrent = key;
                                __ypcurrentlen = keylen;
                        } else {
                                r = yp_first(__ypdomain, "group.byname",
                                    &__ypcurrent, &__ypcurrentlen,
                                    &data, &datalen);
                        }
                        if (r) {
                                __ypmode = 0;
                                __ypcurrent = NULL;
                                if (r == YPERR_NOMORE)
                                        continue;
                                else
                                        return 0;
                        }
                        bcopy(data, line, datalen);
                        free(data);
                        line[datalen] = '\0';
                        bp = line;
                        goto parse;
                }
#endif
                if (!fgets(line, sizeof(gs->line), _gr_fp)) {
                        if (feof(_gr_fp) && !ferror(_gr_fp))
                                errno = saved_errno;
                        return 0;
                }
                bp = line;
                /* skip lines that are too big */
                if (!strchr(line, '\n')) {
                        int ch;

                        while ((ch = getc_unlocked(_gr_fp)) != '\n' &&
                            ch != EOF)
                                ;
                        continue;
                }
#ifdef YP
                if (line[0] == '+' || line[0] == '-') {
                        if (!__ypdomain)
                                yp_get_default_domain(&__ypdomain);
                }
                if (line[0] == '+') {
                        switch (line[1]) {
                        case ':':
                        case '\0':
                        case '\n':
                                if (foundyp) {
                                        *foundyp = 1;
                                        errno = saved_errno;
                                        return 0;
                                }
                                if (!search) {
                                        __ypmode = 1;
                                        continue;
                                }
                                if (name) {
                                        r = yp_match(__ypdomain,
                                            "group.byname", name, strlen(name),
                                            &data, &datalen);
                                } else {
                                        char buf[20];
                                        snprintf(buf, sizeof buf, "%u", gid);
                                        r = yp_match(__ypdomain, "group.bygid",
                                            buf, strlen(buf), &data, &datalen);
                                }
                                switch (r) {
                                case 0:
                                        break;
                                case YPERR_KEY:
                                        continue;
                                default:
                                        return 0;
                                }
                                bcopy(data, line, datalen);
                                free(data);
                                line[datalen] = '\0';
                                bp = line;
                                p_gr->gr_name = strsep(&bp, ":\n");
                                if (__ypexclude_is(&__ypexhead, p_gr->gr_name))
                                        continue;
                                p_gr->gr_passwd = strsep(&bp, ":\n");
                                if (!(cp = strsep(&bp, ":\n")))
                                        continue;
                                if (name) {
                                        ul = strtoul(cp, &endp, 10);
                                        if (*endp != '\0' || endp == cp ||
                                            ul >= GID_MAX)
                                                continue;
                                        p_gr->gr_gid = ul;
                                } else
                                        p_gr->gr_gid = gid;
                                goto found_it;
                        default:
                                bp = strsep(&bp, ":\n") + 1;
                                if ((search && name && strcmp(bp, name)) ||
                                    __ypexclude_is(&__ypexhead, bp))
                                        continue;
                                r = yp_match(__ypdomain, "group.byname",
                                    bp, strlen(bp), &data, &datalen);
                                switch (r) {
                                case 0:
                                        break;
                                case YPERR_KEY:
                                        continue;
                                default:
                                        return 0;
                                }
                                bcopy(data, line, datalen);
                                free(data);
                                line[datalen] = '\0';
                                bp = line;
                        }
                } else if (line[0] == '-') {
                        if (__ypexclude_add(&__ypexhead,
                            strsep(&line, ":\n") + 1))
                                return 0;
                        if (foundyp) {
                                *foundyp = -1;
                                errno = saved_errno;
                                return 0;
                        }
                        continue;
                }
parse:
#endif
                p_gr->gr_name = strsep(&bp, ":\n");
                if (search && name && strcmp(p_gr->gr_name, name))
                        continue;
#ifdef YP
                if (__ypmode && __ypexclude_is(&__ypexhead, p_gr->gr_name))
                        continue;
#endif
                p_gr->gr_passwd = strsep(&bp, ":\n");
                if (!(cp = strsep(&bp, ":\n")))
                        continue;
                ul = strtoul(cp, &endp, 10);
                if (endp == cp || *endp != '\0' || ul >= GID_MAX)
                        continue;
                p_gr->gr_gid = ul;
                if (search && name == NULL && p_gr->gr_gid != gid)
                        continue;
#ifdef YP
        found_it:
#endif
                cp = NULL;
                if (bp == NULL)
                        continue;
                for (m = p_gr->gr_mem = members;; bp++) {
                        if (m == &members[MAXGRP - 1])
                                break;
                        if (*bp == ',') {
                                if (cp) {
                                        *bp = '\0';
                                        *m++ = cp;
                                        cp = NULL;
                                }
                        } else if (*bp == '\0' || *bp == '\n' || *bp == ' ') {
                                if (cp) {
                                        *bp = '\0';
                                        *m++ = cp;
                                }
                                break;
                        } else if (cp == NULL)
                                cp = bp;
                }
                *m = NULL;
                errno = saved_errno;
                return 1;
        }
        /* NOTREACHED */
}