/*-
 * Copyright (C) 1996
 *      David L. Nugent.  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.
 *
 * THIS SOFTWARE IS PROVIDED BY DAVID L. NUGENT 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 DAVID L. NUGENT 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.
 *
 * $FreeBSD: src/usr.sbin/pw/edgroup.c,v 1.9 2004/03/08 20:31:37 kensmith Exp $
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <pwd.h>
#include <grp.h>
#include <fcntl.h>
#include <sys/param.h>
#include <ctype.h>

#include "pwupd.h"

static int
isingroup(char const * name, char **mem)
{
        int             i;

        for (i = 0; mem[i] != NULL; i++)
                if (strcmp(name, mem[i]) == 0)
                        return i;
        return -1;
}

int
editgroups(char *name, char **groups)
{
        int             rc = 0;
        int             infd;
        char            groupfile[MAXPATHLEN];
        char            grouptmp[MAXPATHLEN];

        strncpy(groupfile, getgrpath(_GROUP), MAXPATHLEN - 5);
        groupfile[MAXPATHLEN - 5] = '\0';
        strcpy(grouptmp, groupfile);
        strcat(grouptmp, ".new");

        if ((infd = open(groupfile, O_RDWR | O_CREAT | O_EXLOCK, 0644)) != -1) {
                FILE           *infp;

                if ((infp = fdopen(infd, "r+")) == NULL)
                        close(infd);
                else {
                        int             outfd;

                        if ((outfd = open(grouptmp, O_RDWR | O_CREAT | O_TRUNC, 0644)) != -1) {
                                FILE           *outfp;

                                if ((outfp = fdopen(outfd, "w+")) == NULL)
                                        close(outfd);
                                else {
                                        int             linelen = PWBUFSZ;
                                        int             outlen =  PWBUFSZ;
                                        int             memlen = 200; /* Arbitrary */
                                        char           *line = malloc(linelen);
                                        char           *outl = malloc(outlen);
                                        char          **mems = malloc(memlen * sizeof(char *));
                                        int             namlen = strlen(name);

                                        if (line == NULL || outl == NULL || mems == NULL) {
                                            mem_abort:
                                                rc = 0;
                                        } else {
                                                while (fgets(line, linelen, infp) != NULL) {
                                                        char           *p;
                                                        int             l;

                                                        while ((p = strchr(line, '\n')) == NULL)
                                                        {
                                                                if (extendline(&line, &linelen, linelen + PWBUFSZ) == -1) {
                                                                        goto mem_abort;
                                                                }
                                                                l = strlen(line);
                                                                if (fgets(line + l, linelen - l, infp) == NULL)
                                                                        break;  /* No newline terminator on last line */
                                                        }
                                                        l = strlen(line) + namlen + 1;
                                                        if (extendline(&outl, &outlen, l) == -1) {
                                                                goto mem_abort;
                                                        }
                                                        if (*line == '#')
                                                                strcpy(outl, line);
                                                        else if (*line == '\n')
                                                                *outl = '\0';
                                                        else {
                                                                int             i,
                                                                                mno = 0;
                                                                char           *cp = line;
                                                                char const     *sep = ":\n";
                                                                struct group    grp;

                                                                memset(&grp, 0, sizeof grp);
                                                                for (i = 0; (p = strsep(&cp, sep)) != NULL; i++) {
                                                                        switch (i) {
                                                                        case 0: /* Group name */
                                                                                grp.gr_name = p;
                                                                                break;
                                                                        case 1: /* Group password */
                                                                                grp.gr_passwd = p;
                                                                                break;
                                                                        case 2: /* Group id */
                                                                                grp.gr_gid = atoi(p);
                                                                                break;
                                                                        case 3: /* Member list */
                                                                                cp = p;
                                                                                sep = ",\n";
                                                                                break;
                                                                        default:        /* Individual members */
                                                                                if (*p) {
                                                                                        if (extendarray(&mems, &memlen, mno + 2) == -1) {
                                                                                                goto mem_abort;
                                                                                        }
                                                                                        mems[mno++] = p;
                                                                                }
                                                                                break;
                                                                        }
                                                                }
                                                                if (i < 2)      /* Bail out - insufficient fields */
                                                                        continue;

                                                                grp.gr_mem = mems;
                                                                for (i = mno; i < memlen; i++)
                                                                        mems[i] = NULL;

                                                                /*
                                                                 * Delete from group, or add to group?
                                                                 */
                                                                if (groups == NULL || isingroup(grp.gr_name, groups) == -1) {   /* Delete */
                                                                        int             idx;

                                                                        while ((idx = isingroup(name, mems)) != -1) {
                                                                                for (i = idx; i < (memlen - 1); i++)
                                                                                        mems[i] = mems[i + 1];
                                                                                mems[i] = NULL;
                                                                                --mno;
                                                                        }
                                                                        /*
                                                                         * Special case - deleting user and group may be user's own
                                                                         */
                                                                        if (groups == NULL && mems[0] == NULL && strcmp(name, grp.gr_name) == 0) {
                                                                                /*
                                                                                 * First, make _sure_ we don't have other members
                                                                                 */
                                                                                struct passwd  *pwd;

                                                                                SETPWENT();
                                                                                while ((pwd = GETPWENT()) != NULL && (gid_t)pwd->pw_gid != (gid_t)grp.gr_gid);
                                                                                ENDPWENT();
                                                                                if (pwd == NULL)        /* No members at all */
                                                                                        continue;       /* Drop the group */
                                                                        }
                                                                } else if (isingroup(name, mems) == -1) {
                                                                        if (extendarray(&mems, &memlen, mno + 2) == -1) {
                                                                                goto mem_abort;
                                                                        }
                                                                        grp.gr_mem = mems;    /* May have realloced() */
                                                                        mems[mno++] = name;
                                                                        mems[mno  ] = NULL;
                                                                }
                                                                fmtgrentry(&outl, &outlen, &grp, PWF_GROUP);
                                                        }
                                                        fputs(outl, outfp);
                                                }
                                                if (fflush(outfp) != EOF) {
                                                        rc = 1;

                                                        /*
                                                         * Copy data back into the original file and truncate
                                                         */
                                                        rewind(infp);
                                                        rewind(outfp);
                                                        while (fgets(outl, outlen, outfp) != NULL)
                                                                fputs(outl, infp);

                                                        /*
                                                         * This is a gross hack, but we may have corrupted the
                                                         * original file.
                                                         */
                                                        if (fflush(infp) == EOF || ferror(infp))
                                                                rc = rename(grouptmp, groupfile) == 0;
                                                        else
                                                                ftruncate(infd, ftell(infp));
                                                }
                                        }
                                        free(mems);
                                        free(outl);
                                        free(line);
                                        fclose(outfp);
                                }
                                remove(grouptmp);
                        }
                        fclose(infp);
                }
        }
        return rc;
}