00709a7737
Replaces commands/write. No Minix-specific changes needed. The NetBSD version lacks a few features that were present in the Minix version: cbreak mode, verbose, and shell escapes, but the main write(1) functionality is there and working. Change-Id: I87b9589c54d3595d26247d221bb3d1f613feeb8c
138 lines
3.9 KiB
C
138 lines
3.9 KiB
C
/* $NetBSD: term_chk.c,v 1.8 2009/04/14 07:59:17 lukem Exp $ */
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/*
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* Copyright (c) 1989, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Jef Poskanzer and Craig Leres of the Lawrence Berkeley Laboratory.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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#ifndef lint
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__RCSID("$NetBSD: term_chk.c,v 1.8 2009/04/14 07:59:17 lukem Exp $");
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#endif
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#include <sys/types.h>
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#include <sys/param.h>
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#include <sys/stat.h>
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#include <time.h>
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#include <stdio.h>
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#include <errno.h>
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#include <unistd.h>
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#include <paths.h>
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#include <fcntl.h>
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#include <string.h>
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#include <err.h>
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#include "term_chk.h"
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/*
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* term_chk - check that a terminal exists, and get the message bit
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* and the access time
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*/
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int
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term_chk(uid_t uid, const char *tty, int *msgsokP, time_t *atimeP, int ismytty,
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gid_t saved_egid)
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{
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char path[MAXPATHLEN];
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struct stat s;
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int i, fd, serrno;
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if (strstr(tty, "../") != NULL) {
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errno = EINVAL;
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return -1;
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}
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i = snprintf(path, sizeof path, _PATH_DEV "%s", tty);
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if (i < 0 || i >= (int)sizeof(path)) {
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errno = ENOMEM;
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return -1;
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}
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(void)setegid(saved_egid);
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fd = open(path, O_WRONLY, 0);
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serrno = errno;
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(void)setegid(getgid());
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errno = serrno;
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if (fd == -1)
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return(-1);
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if (fstat(fd, &s) == -1)
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goto error;
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if (!isatty(fd))
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goto error;
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if (s.st_uid != uid && uid != 0) {
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errno = EPERM;
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goto error;
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}
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if (msgsokP)
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*msgsokP = (s.st_mode & S_IWGRP) != 0; /* group write bit */
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if (atimeP)
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*atimeP = s.st_atime;
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if (ismytty)
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(void)close(fd);
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return ismytty ? 0 : fd;
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error:
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if (fd != -1) {
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serrno = errno;
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(void)close(fd);
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errno = serrno;
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}
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return -1;
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}
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char *
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check_sender(time_t *atime, uid_t myuid, gid_t saved_egid)
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{
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int myttyfd;
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int msgsok;
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char *mytty;
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/* check that sender has write enabled */
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if (isatty(fileno(stdin)))
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myttyfd = fileno(stdin);
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else if (isatty(fileno(stdout)))
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myttyfd = fileno(stdout);
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else if (isatty(fileno(stderr)))
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myttyfd = fileno(stderr);
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else if (atime == NULL)
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return NULL;
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else
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errx(1, "Cannot find your tty");
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if ((mytty = ttyname(myttyfd)) == NULL)
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err(1, "Cannot find the name of your tty");
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if (strncmp(mytty, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
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mytty += sizeof(_PATH_DEV) - 1;
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if (term_chk(myuid, mytty, &msgsok, atime, 1, saved_egid) == -1)
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err(1, "%s%s", _PATH_DEV, mytty);
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if (!msgsok) {
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warnx(
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"You have write permission turned off; no reply possible");
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}
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return mytty;
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}
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