/*-
 * 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/pw_group.c,v 1.16 2008/02/23 01:25:22 scf Exp $
 */

#include <ctype.h>
#include <err.h>
#include <termios.h>
#include <stdbool.h>
#include <unistd.h>

#include "pw.h"
#include "bitmap.h"


static struct passwd *lookup_pwent(const char *user);
static void     delete_members(char ***members, int *grmembers, int *i,
    struct carg *arg, struct group *grp);
static int      print_group(struct group * grp, int pretty);
static gid_t    gr_gidpolicy(struct userconf * cnf, struct cargs * args);

static
int
alldigits(const char *str)
{
        while (*str) {
                if (*str < '0' || *str > '9')
                        return(0);
                ++str;
        }
        return(1);
}

int
pw_group(struct userconf * cnf, int mode, struct cargs * args)
{
        int             rc;
        struct carg    *a_name = getarg(args, 'n');
        struct carg    *a_gid = getarg(args, 'g');
        struct carg    *arg;
        struct group   *grp = NULL;
        int             grmembers = 0;
        char           **members = NULL;

        static struct group fakegroup =
        {
                "nogroup",
                "*",
                -1,
                NULL
        };

        if (mode == M_LOCK || mode == M_UNLOCK)
                errx(EX_USAGE, "'lock' command is not available for groups");

        /*
         * With M_NEXT, we only need to return the
         * next gid to stdout
         */
        if (mode == M_NEXT) {
                gid_t next = gr_gidpolicy(cnf, args);
                if (getarg(args, 'q'))
                        return next;
                printf("%ld\n", (long)next);
                return EXIT_SUCCESS;
        }

        if (mode == M_PRINT && getarg(args, 'a')) {
                int             pretty = getarg(args, 'P') != NULL;

                SETGRENT();
                while ((grp = GETGRENT()) != NULL)
                        print_group(grp, pretty);
                ENDGRENT();
                return EXIT_SUCCESS;
        }
        if (a_gid == NULL) {
                if (a_name == NULL)
                        errx(EX_DATAERR, "group name or id required");

                if (mode != M_ADD && grp == NULL && alldigits(a_name->val)) {
                        (a_gid = a_name)->ch = 'g';
                        a_name = NULL;
                }
        }
        grp = (a_name != NULL) ? GETGRNAM(a_name->val) : GETGRGID((gid_t) atoi(a_gid->val));

        if (mode == M_UPDATE || mode == M_DELETE || mode == M_PRINT) {
                if (a_name == NULL && grp == NULL)      /* Try harder */
                        grp = GETGRGID(atoi(a_gid->val));

                if (grp == NULL) {
                        if (mode == M_PRINT && getarg(args, 'F')) {
                                char    *fmems[1];
                                fmems[0] = NULL;
                                fakegroup.gr_name = a_name ? a_name->val : "nogroup";
                                fakegroup.gr_gid = a_gid ? (gid_t) atol(a_gid->val) : -1;
                                fakegroup.gr_mem = fmems;
                                return print_group(&fakegroup, getarg(args, 'P') != NULL);
                        }
                        errx(EX_DATAERR, "unknown group `%s'", a_name ? a_name->val : a_gid->val);
                }
                if (a_name == NULL)     /* Needed later */
                        a_name = addarg(args, 'n', grp->gr_name);

                /*
                 * Handle deletions now
                 */
                if (mode == M_DELETE) {
                        gid_t           gid = grp->gr_gid;

                        rc = delgrent(grp);
                        if (rc == -1)
                                err(EX_IOERR, "group '%s' not available (NIS?)", grp->gr_name);
                        else if (rc != 0) {
                                warn("group update");
                                return EX_IOERR;
                        }
                        pw_log(cnf, mode, W_GROUP, "%s(%ld) removed", a_name->val, (long) gid);
                        return EXIT_SUCCESS;
                } else if (mode == M_PRINT)
                        return print_group(grp, getarg(args, 'P') != NULL);

                if (a_gid)
                        grp->gr_gid = (gid_t) atoi(a_gid->val);

                if ((arg = getarg(args, 'l')) != NULL)
                        grp->gr_name = pw_checkname((u_char *)arg->val, 0);
        } else {
                if (a_name == NULL)     /* Required */
                        errx(EX_DATAERR, "group name required");
                else if (grp != NULL)   /* Exists */
                        errx(EX_DATAERR, "group name `%s' already exists", a_name->val);

                extendarray(&members, &grmembers, 200);
                members[0] = NULL;
                grp = &fakegroup;
                grp->gr_name = pw_checkname((u_char *)a_name->val, 0);
                grp->gr_passwd = "*";
                grp->gr_gid = gr_gidpolicy(cnf, args);
                grp->gr_mem = members;
        }

        /*
         * This allows us to set a group password Group passwords is an
         * antique idea, rarely used and insecure (no secure database) Should
         * be discouraged, but it is apparently still supported by some
         * software.
         */

        if ((arg = getarg(args, 'h')) != NULL ||
            (arg = getarg(args, 'H')) != NULL) {
                if (strcmp(arg->val, "-") == 0)
                        grp->gr_passwd = "*";   /* No access */
                else {
                        int             fd = atoi(arg->val);
                        int             precrypt = (arg->ch == 'H');
                        int             b;
                        int             istty = isatty(fd);
                        struct termios  t;
                        char           *p, line[256];

                        if (istty) {
                                if (tcgetattr(fd, &t) == -1)
                                        istty = 0;
                                else {
                                        struct termios  n = t;

                                        /* Disable echo */
                                        n.c_lflag &= ~(ECHO);
                                        tcsetattr(fd, TCSANOW, &n);
                                        printf("%sassword for group %s:", (mode == M_UPDATE) ? "New p" : "P", grp->gr_name);
                                        fflush(stdout);
                                }
                        }
                        b = read(fd, line, sizeof(line) - 1);
                        if (istty) {    /* Restore state */
                                tcsetattr(fd, TCSANOW, &t);
                                fputc('\n', stdout);
                                fflush(stdout);
                        }
                        if (b < 0) {
                                warn("-h file descriptor");
                                return EX_OSERR;
                        }
                        line[b] = '\0';
                        if ((p = strpbrk(line, " \t\r\n")) != NULL)
                                *p = '\0';
                        if (!*line)
                                errx(EX_DATAERR, "empty password read on file descriptor %d", fd);
                        if (precrypt) {
                                if (strchr(line, ':') != NULL)
                                        return EX_DATAERR;
                                grp->gr_passwd = line;
                        } else
                                grp->gr_passwd = pw_pwcrypt(line);
                }
        }

        if (((arg = getarg(args, 'M')) != NULL ||
            (arg = getarg(args, 'd')) != NULL ||
            (arg = getarg(args, 'm')) != NULL) && arg->val) {
                int     i = 0;
                char   *p;
                struct passwd   *pwd;

                /* Make sure this is not stay NULL with -M "" */
                extendarray(&members, &grmembers, 200);
                if (arg->ch == 'd')
                        delete_members(&members, &grmembers, &i, arg, grp);
                else if (arg->ch == 'm') {
                        int     k = 0;

                        while (grp->gr_mem[k] != NULL) {
                                if (extendarray(&members, &grmembers, i + 2) != -1)
                                        members[i++] = grp->gr_mem[k];
                                k++;
                        }
                }

                if (arg->ch != 'd')
                        for (p = strtok(arg->val, ", \t"); p != NULL; p = strtok(NULL, ", \t")) {
                                int     j;

                                /*
                                 * Check for duplicates
                                 */
                                pwd = lookup_pwent(p);
                                for (j = 0; j < i && strcmp(members[j], pwd->pw_name) != 0; j++)
                                        ;
                                if (j == i && extendarray(&members, &grmembers, i + 2) != -1)
                                        members[i++] = newstr(pwd->pw_name);
                        }
                while (i < grmembers)
                        members[i++] = NULL;
                grp->gr_mem = members;
        }

        if (getarg(args, 'N') != NULL)
                return print_group(grp, getarg(args, 'P') != NULL);

        if (mode == M_ADD && (rc = addgrent(grp)) != 0) {
                if (rc == -1)
                        warnx("group '%s' already exists", grp->gr_name);
                else
                        warn("group update");
                return EX_IOERR;
        } else if (mode == M_UPDATE && (rc = chggrent(a_name->val, grp)) != 0) {
                if (rc == -1)
                        warnx("group '%s' not available (NIS?)", grp->gr_name);
                else
                        warn("group update");
                return EX_IOERR;
        }
        /* grp may have been invalidated */
        if ((grp = GETGRNAM(a_name->val)) == NULL)
                errx(EX_SOFTWARE, "group disappeared during update");

        pw_log(cnf, mode, W_GROUP, "%s(%ld)", grp->gr_name, (long) grp->gr_gid);

        if (members)
                free(members);

        return EXIT_SUCCESS;
}


/*
 * Lookup a passwd entry using a name or UID.
 */
static struct passwd *
lookup_pwent(const char *user)
{
        struct passwd *pwd;

        if ((pwd = GETPWNAM(user)) == NULL &&
            (!isdigit((unsigned char)*user) ||
            (pwd = getpwuid((uid_t) atoi(user))) == NULL))
                errx(EX_NOUSER, "user `%s' does not exist", user);

        return (pwd);
}


/*
 * Delete requested members from a group.
 */
static void
delete_members(char ***members, int *grmembers, int *i, struct carg *arg,
    struct group *grp)
{
        bool matchFound;
        char *user;
        char *valueCopy;
        char *valuePtr;
        int k;
        struct passwd *pwd;

        k = 0;
        while (grp->gr_mem[k] != NULL) {
                matchFound = false;
                if ((valueCopy = strdup(arg->val)) == NULL)
                        errx(EX_UNAVAILABLE, "out of memory");
                valuePtr = valueCopy;
                while ((user = strsep(&valuePtr, ", \t")) != NULL) {
                        pwd = lookup_pwent(user);
                        if (strcmp(grp->gr_mem[k], pwd->pw_name) == 0) {
                                matchFound = true;
                                break;
                        }
                }
                free(valueCopy);

                if (!matchFound &&
                    extendarray(members, grmembers, *i + 2) != -1)
                        (*members)[(*i)++] = grp->gr_mem[k];

                k++;
        }

        return;
}


static          gid_t
gr_gidpolicy(struct userconf * cnf, struct cargs * args)
{
        struct group   *grp;
        gid_t           gid = (gid_t) - 1;
        struct carg    *a_gid = getarg(args, 'g');

        /*
         * Check the given gid, if any
         */
        if (a_gid != NULL) {
                gid = (gid_t) atol(a_gid->val);

                if ((grp = GETGRGID(gid)) != NULL && getarg(args, 'o') == NULL)
                        errx(EX_DATAERR, "gid `%ld' has already been allocated", (long) grp->gr_gid);
        } else {
                struct bitmap   bm;

                /*
                 * We need to allocate the next available gid under one of
                 * two policies a) Grab the first unused gid b) Grab the
                 * highest possible unused gid
                 */
                if (cnf->min_gid >= cnf->max_gid) {     /* Sanity claus^H^H^H^Hheck */
                        cnf->min_gid = 1000;
                        cnf->max_gid = 32000;
                }
                bm = bm_alloc(cnf->max_gid - cnf->min_gid + 1);

                /*
                 * Now, let's fill the bitmap from the password file
                 */
                SETGRENT();
                while ((grp = GETGRENT()) != NULL)
                        if ((gid_t)grp->gr_gid >= (gid_t)cnf->min_gid &&
                            (gid_t)grp->gr_gid <= (gid_t)cnf->max_gid)
                                bm_setbit(&bm, grp->gr_gid - cnf->min_gid);
                ENDGRENT();

                /*
                 * Then apply the policy, with fallback to reuse if necessary
                 */
                if (cnf->reuse_gids)
                        gid = (gid_t) (bm_firstunset(&bm) + cnf->min_gid);
                else {
                        gid = (gid_t) (bm_lastset(&bm) + 1);
                        if (!bm_isset(&bm, gid))
                                gid += cnf->min_gid;
                        else
                                gid = (gid_t) (bm_firstunset(&bm) + cnf->min_gid);
                }

                /*
                 * Another sanity check
                 */
                if (gid < cnf->min_gid || gid > cnf->max_gid)
                        errx(EX_SOFTWARE, "unable to allocate a new gid - range fully used");
                bm_dealloc(&bm);
        }
        return gid;
}


static int
print_group(struct group * grp, int pretty)
{
        if (!pretty) {
                int             buflen = 0;
                char           *buf = NULL;

                fmtgrent(&buf, &buflen, grp);
                fputs(buf, stdout);
                free(buf);
        } else {
                int             i;

                printf("Group Name: %-15s   #%lu\n"
                       "   Members: ",
                       grp->gr_name, (long) grp->gr_gid);
                for (i = 0; grp->gr_mem[i]; i++)
                        printf("%s%s", i ? "," : "", grp->gr_mem[i]);
                fputs("\n\n", stdout);
        }
        return EXIT_SUCCESS;
}