oamuser/user/groups.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */


#pragma ident   "%Z%%M% %I% %E% SMI"

#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <sys/stat.h>
#include <grp.h>
#include <unistd.h>
#include <userdefs.h>
#include <errno.h>
#include <limits.h>
#include "users.h"
#include "messages.h"

#define MYBUFSIZE (LINE_MAX)
    /* Corresponds to MYBUFSIZE in grpck.c, BUFCONST in nss_dbdefs.c */

int
edit_group(char *login, char *new_login, gid_t gids[], int overwrite)
{
    char **memptr;
    char t_name[] = "/etc/gtmp.XXXXXX";
    int fd;
    FILE *e_fptr, *t_fptr;
    struct group *g_ptr;    /* group structure from fgetgrent */
    int i;
    int modified = 0;
    struct stat sbuf;

    int bufsize, g_length, sav_errno;
    long g_curr = 0L;
    char *g_string, *new_g_string, *gstr_off;

    if ((e_fptr = fopen(GROUP, "r")) == NULL)
        return (EX_UPDATE);

    if (fstat(fileno(e_fptr), &sbuf) != 0) {
        (void) fclose(e_fptr);
        return (EX_UPDATE);
    }

    if ((fd = mkstemp(t_name)) == -1) {
        (void) fclose(e_fptr);
        return (EX_UPDATE);
    }

    if ((t_fptr = fdopen(fd, "w")) == NULL) {
        (void) close(fd);
        (void) unlink(t_name);
        (void) fclose(e_fptr);
        return (EX_UPDATE);
    }

    /*
     * Get ownership and permissions correct
     */

    if (fchmod(fd, sbuf.st_mode) != 0 ||
        fchown(fd, sbuf.st_uid, sbuf.st_gid) != 0) {
        (void) fclose(t_fptr);
        (void) fclose(e_fptr);
        (void) unlink(t_name);
        return (EX_UPDATE);
    }

    g_curr = ftell(e_fptr);

    /* Make TMP file look like we want GROUP file to look */

    bufsize = MYBUFSIZE;
    if ((g_string = malloc(bufsize)) == NULL) {
        (void) fclose(t_fptr);
        (void) fclose(e_fptr);
        (void) unlink(t_name);
        return (EX_UPDATE);
    }
    /*
     * bufsize contains the size of the currently allocated buffer
     * buffer size, which is initially MYBUFSIZE but when a line
     * greater than MYBUFSIZE is encountered then bufsize gets increased
     * by MYBUFSIZE.
     * g_string always points to the beginning of the buffer (even after
     * realloc()).
     * gstr_off = g_string + MYBUFSIZE * (n), where n >= 0.
     */
    while (!feof(e_fptr) && !ferror(e_fptr)) {
        g_length = 0;
        gstr_off = g_string;
        while (fgets(gstr_off, (bufsize - g_length), e_fptr) != NULL) {
            g_length += strlen(gstr_off);
            if (g_string[g_length - 1] == '\n' || feof(e_fptr))
                break;
            new_g_string = realloc(g_string, (bufsize + MYBUFSIZE));
            if (new_g_string == NULL) {
                free(g_string);
                (void) fclose(t_fptr);
                (void) fclose(e_fptr);
                (void) unlink(t_name);
                return (EX_UPDATE);
            }
            bufsize += MYBUFSIZE;
            g_string = new_g_string;
            gstr_off = g_string + g_length;
        }
        if (g_length == 0) {
            continue;
        }

        /* While there is another group string */

        (void) fseek(e_fptr, g_curr, SEEK_SET);
        errno = 0;
        g_ptr = fgetgrent(e_fptr);
        sav_errno = errno;
        g_curr = ftell(e_fptr);

        if (g_ptr == NULL) {
            /* tried to parse a group string over MYBUFSIZ char */
            if (sav_errno == ERANGE)
                errmsg(M_GROUP_ENTRY_OVF);
            else
                errmsg(M_READ_ERROR);

            modified = 0; /* bad group file: cannot rebuild */
            break;
        }

        /* first delete the login from the group, if it's there */
        if (overwrite || !gids) {
            if (g_ptr->gr_mem != NULL) {
                for (memptr = g_ptr->gr_mem; *memptr;
                    memptr++) {
                    if (strcmp(*memptr, login) == 0) {
                        /* Delete this one */
                        char **from = memptr + 1;

                        g_length -= (strlen(*memptr)+1);

                        do {
                            *(from - 1) = *from;
                        } while (*from++);

                        modified++;
                        break;
                    }
                }
            }
        }

        /* now check to see if group is one to add to */
        if (gids) {
            for (i = 0; gids[i] != -1; i++) {
                if (g_ptr->gr_gid == gids[i]) {
                    /* Find end */
                    for (memptr = g_ptr->gr_mem; *memptr;
                        memptr++)
                        ;
                    g_length += strlen(new_login ?
                            new_login : login)+1;

                    *memptr++ = new_login ?
                        new_login : login;
                    *memptr = NULL;

                    modified++;
                }
            }
        }
        putgrent(g_ptr, t_fptr);
    }
    free(g_string);

    (void) fclose(e_fptr);

    if (fclose(t_fptr) != 0) {
        (void) unlink(t_name);
        return (EX_UPDATE);
    }

    /* Now, update GROUP file, if it was modified */
    if (modified) {
        if (rename(t_name, GROUP) != 0) {
            (void) unlink(t_name);
            return (EX_UPDATE);
        }
        return (EX_SUCCESS);
    } else {
        (void) unlink(t_name);
        return (EX_SUCCESS);
    }
}