xref: /freebsd-11-stable/usr.sbin/pw/pw_group.c

/*-
 * 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.
 */

#ifndef lint
static const char rcsid[] =
  "$FreeBSD: head/usr.sbin/pw/pw_group.c 285411 2015-07-11 22:35:07Z bapt $";
#endif /* not lint */

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

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


static struct passwd *lookup_pwent(const char *user);
static void	delete_members(struct group *grp, char *list);
static int	print_group(struct group * grp);
static gid_t    gr_gidpolicy(struct userconf * cnf, long id);

static void
set_passwd(struct group *grp, bool update)
{
	int		 b;
	int		 istty;
	struct termios	 t, n;
	char		*p, line[256];

	if (conf.fd == '-') {
		grp->gr_passwd = "*";	/* No access */
		return;
	}

	if ((istty = isatty(conf.fd))) {
		n = t;
		/* Disable echo */
		n.c_lflag &= ~(ECHO);
		tcsetattr(conf.fd, TCSANOW, &n);
		printf("%sassword for group %s:", update ? "New p" : "P",
		    grp->gr_name);
		fflush(stdout);
	}
	b = read(conf.fd, line, sizeof(line) - 1);
	if (istty) {	/* Restore state */
		tcsetattr(conf.fd, TCSANOW, &t);
		fputc('\n', stdout);
		fflush(stdout);
	}
	if (b < 0)
		err(EX_OSERR, "-h file descriptor");
	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",
		    conf.fd);
	if (conf.precrypted) {
		if (strchr(line, ':') != 0)
			errx(EX_DATAERR, "wrong encrypted passwrd");
		grp->gr_passwd = line;
	} else
		grp->gr_passwd = pw_pwcrypt(line);
}

int
pw_groupnext(struct userconf *cnf, bool quiet)
{
	gid_t next = gr_gidpolicy(cnf, -1);

	if (quiet)
		return (next);
	printf("%u\n", next);

	return (EXIT_SUCCESS);
}

static int
pw_groupshow(const char *name, long id, struct group *fakegroup)
{
	struct group *grp = NULL;

	if (id < 0 && name == NULL && !conf.all)
		errx(EX_DATAERR, "groupname or id or '-a' required");

	if (conf.all) {
		SETGRENT();
		while ((grp = GETGRENT()) != NULL)
			print_group(grp);
		ENDGRENT();

		return (EXIT_SUCCESS);
	}

	grp = (name != NULL) ? GETGRNAM(name) : GETGRGID(id);
	if (grp == NULL) {
		if (conf.force) {
			grp = fakegroup;
		} else {
			if (name == NULL)
				errx(EX_DATAERR, "unknown gid `%ld'", id);
			errx(EX_DATAERR, "unknown group `%s'", name);
		}
	}

	return (print_group(grp));
}

static int
pw_groupdel(const char *name, long id)
{
	struct group *grp = NULL;
	int rc;

	grp = (name != NULL) ? GETGRNAM(name) : GETGRGID(id);
	if (grp == NULL) {
		if (name == NULL)
			errx(EX_DATAERR, "unknown gid `%ld'", id);
		errx(EX_DATAERR, "unknown group `%s'", name);
	}

	rc = delgrent(grp);
	if (rc == -1)
		err(EX_IOERR, "group '%s' not available (NIS?)", name);
	else if (rc != 0)
		err(EX_IOERR, "group update");
	pw_log(conf.userconf, M_DELETE, W_GROUP, "%s(%ld) removed", name, id);

	return (EXIT_SUCCESS);
}

int
pw_group(int mode, char *name, long id, struct cargs * args)
{
	int		rc;
	struct carg    *arg;
	struct group   *grp = NULL;
	char           **members = NULL;
	struct userconf	*cnf = conf.userconf;

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

	if (mode == M_NEXT)
		return (pw_groupnext(cnf, conf.quiet));

	if (mode == M_PRINT)
		return (pw_groupshow(name, id, &fakegroup));

	if (mode == M_DELETE)
		return (pw_groupdel(name, id));

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

	if (id < 0 && name == NULL)
		errx(EX_DATAERR, "group name or id required");

	grp = (name != NULL) ? GETGRNAM(name) : GETGRGID(id);

	if (mode == M_UPDATE) {
		if (name == NULL && grp == NULL)	/* Try harder */
			grp = GETGRGID(id);

		if (grp == NULL) {
			if (name == NULL)
				errx(EX_DATAERR, "unknown group `%s'", name);
			else
				errx(EX_DATAERR, "unknown group `%ld'", id);
		}
		if (name == NULL)	/* Needed later */
			name = grp->gr_name;

		if (id > 0)
			grp->gr_gid = (gid_t) id;

		if (conf.newname != NULL)
			grp->gr_name = pw_checkname(conf.newname, 0);
	} else {
		if (name == NULL)	/* Required */
			errx(EX_DATAERR, "group name required");
		else if (grp != NULL)	/* Exists */
			errx(EX_DATAERR, "group name `%s' already exists", name);

		grp = &fakegroup;
		grp->gr_name = pw_checkname(name, 0);
		grp->gr_passwd = "*";
		grp->gr_gid = gr_gidpolicy(cnf, id);
		grp->gr_mem = NULL;
	}

	/*
	 * 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 (conf.which == W_GROUP && conf.fd != -1)
		set_passwd(grp, mode == M_UPDATE);

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

		/* Make sure this is not stay NULL with -M "" */
		if (arg->ch == 'd')
			delete_members(grp, arg->val);
		else if (arg->ch == 'M')
			grp->gr_mem = NULL;

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

			/*
			 * Check for duplicates
			 */
			pwd = lookup_pwent(p);
			for (j = 0; grp->gr_mem != NULL && grp->gr_mem[j] != NULL; j++) {
				if (strcmp(grp->gr_mem[j], pwd->pw_name) == 0)
					break;
			}
			if (grp->gr_mem != NULL && grp->gr_mem[j] != NULL)
				continue;
			grp = gr_add(grp, pwd->pw_name);
		}
	}

	if (conf.dryrun)
		return print_group(grp);

	if (mode == M_ADD && (rc = addgrent(grp)) != 0) {
		if (rc == -1)
			errx(EX_IOERR, "group '%s' already exists",
			    grp->gr_name);
		else
			err(EX_IOERR, "group update");
	} else if (mode == M_UPDATE && (rc = chggrent(name, grp)) != 0) {
		if (rc == -1)
			errx(EX_IOERR, "group '%s' not available (NIS?)",
			    grp->gr_name);
		else
			err(EX_IOERR, "group update");
	}

	if (conf.newname != NULL)
		name = conf.newname;
	/* grp may have been invalidated */
	if ((grp = GETGRNAM(name)) == NULL)
		errx(EX_SOFTWARE, "group disappeared during update");

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

	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(struct group *grp, char *list)
{
	char *p;
	int k;

	if (grp->gr_mem == NULL)
		return;

	for (p = strtok(list, ", \t"); p != NULL; p = strtok(NULL, ", \t")) {
		for (k = 0; grp->gr_mem[k] != NULL; k++) {
			if (strcmp(grp->gr_mem[k], p) == 0)
				break;
		}
		if (grp->gr_mem[k] == NULL) /* No match */
			continue;

		for (; grp->gr_mem[k] != NULL; k++)
			grp->gr_mem[k] = grp->gr_mem[k+1];
	}
}


static          gid_t
gr_gidpolicy(struct userconf * cnf, long id)
{
	struct group   *grp;
	gid_t           gid = (gid_t) - 1;

	/*
	 * Check the given gid, if any
	 */
	if (id > 0) {
		gid = (gid_t) id;

		if ((grp = GETGRGID(gid)) != NULL && conf.checkduplicate)
			errx(EX_DATAERR, "gid `%u' has already been allocated", 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)
{
	if (!conf.pretty) {
		char           *buf = NULL;

		buf = gr_make(grp);
		printf("%s\n", buf);
		free(buf);
	} else {
		int             i;

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