GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.bin/wall/ttymsg.c Lines: 0 70 0.0 %
Date: 2016-12-06 Branches: 0 50 0.0 %

Line Branch Exec Source
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/*	$OpenBSD: ttymsg.c,v 1.17 2015/11/05 22:20:11 benno Exp $	*/
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/*	$NetBSD: ttymsg.c,v 1.3 1994/11/17 07:17:55 jtc 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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 * 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/types.h>
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#include <sys/stat.h>
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#include <sys/uio.h>
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#include <signal.h>
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#include <fcntl.h>
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#include <dirent.h>
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#include <errno.h>
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#include <paths.h>
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#include <unistd.h>
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include <err.h>
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char *ttymsg(struct iovec *, int, char *, int);
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/*
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 * Display the contents of a uio structure on a terminal.  Used by wall(1)
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 * and talkd(8).  Forks and finishes in child if write would block,
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 * waiting up to tmout seconds.  Returns pointer to error string on unexpected
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 * error; string is not newline-terminated.  Various "normal" errors are
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 * ignored (exclusive-use, lack of permission, etc.).
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 */
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char *
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ttymsg(iov, iovcnt, line, tmout)
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	struct iovec *iov;
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	int iovcnt;
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	char *line;
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	int tmout;
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{
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	static char device[MAXNAMLEN] = _PATH_DEV;
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	static char errbuf[1024];
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	int cnt, fd, left, wret;
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	struct iovec localiov[6];
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	int forked = 0;
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	struct stat st;
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	sigset_t mask;
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	if (iovcnt > sizeof(localiov) / sizeof(localiov[0]))
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		return ("too many iov's (change code in wall/ttymsg.c)");
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	/*
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	 * Ignore lines that start with "ftp" or "uucp".
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	 */
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	if ((strncmp(line, "ftp", 3) == 0) ||
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	    (strncmp(line, "uucp", 4) == 0))
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		return (NULL);
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	(void) strlcpy(device + sizeof(_PATH_DEV) - 1, line,
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	    sizeof(device) - (sizeof(_PATH_DEV) - 1));
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	if (strchr(device + sizeof(_PATH_DEV) - 1, '/')) {
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		/* A slash is an attempt to break security... */
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		(void) snprintf(errbuf, sizeof(errbuf), "'/' in \"%s\"",
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		    device);
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		return (errbuf);
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	}
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	if (getuid()) {
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		if (stat(device, &st) < 0)
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			return (NULL);
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		if ((st.st_mode & S_IWGRP) == 0)
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			return (NULL);
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	}
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	/*
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	 * open will fail on slip lines or exclusive-use lines
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	 * if not running as root; not an error.
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	 */
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	if ((fd = open(device, O_WRONLY|O_NONBLOCK, 0)) < 0) {
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		if (errno == EBUSY || errno == EACCES)
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			return (NULL);
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		(void) snprintf(errbuf, sizeof(errbuf),
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		    "%s: %s", device, strerror(errno));
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		return (errbuf);
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	}
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	for (cnt = left = 0; cnt < iovcnt; ++cnt)
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		left += iov[cnt].iov_len;
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	for (;;) {
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		wret = writev(fd, iov, iovcnt);
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		if (wret >= left)
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			break;
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		if (wret >= 0) {
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			left -= wret;
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			if (iov != localiov) {
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				bcopy(iov, localiov,
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				    iovcnt * sizeof(struct iovec));
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				iov = localiov;
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			}
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			for (cnt = 0; wret >= iov->iov_len; ++cnt) {
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				wret -= iov->iov_len;
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				++iov;
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				--iovcnt;
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			}
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			if (wret) {
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				char *base = iov->iov_base;
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				iov->iov_base = base + wret;
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				iov->iov_len -= wret;
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			}
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			continue;
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		}
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		if (errno == EWOULDBLOCK) {
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			int off = 0;
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			pid_t cpid;
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			if (forked) {
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				(void) close(fd);
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				_exit(1);
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			}
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			cpid = fork();
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			if (cpid < 0) {
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				(void) snprintf(errbuf, sizeof(errbuf),
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				    "fork: %s", strerror(errno));
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				(void) close(fd);
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				return (errbuf);
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			}
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			if (cpid) {	/* parent */
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				(void) close(fd);
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				return (NULL);
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			}
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			if (pledge("stdio wpath cpath rpath", NULL) == -1)
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				err(1, "pledge");
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			forked++;
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			/* wait at most tmout seconds */
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			(void) signal(SIGALRM, SIG_DFL);
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			(void) signal(SIGTERM, SIG_DFL); /* XXX */
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			(void) sigemptyset(&mask);
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			(void) sigprocmask(SIG_SETMASK, &mask, NULL);
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			(void) alarm((u_int)tmout);
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			(void) fcntl(fd, O_NONBLOCK, &off);
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			continue;
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		}
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		/*
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		 * We get ENODEV on a slip line if we're running as root,
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		 * and EIO if the line just went away.
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		 */
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		if (errno == ENODEV || errno == EIO)
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			break;
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		(void) close(fd);
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		if (forked)
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			_exit(1);
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		(void) snprintf(errbuf, sizeof(errbuf),
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		    "%s: %s", device, strerror(errno));
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		return (errbuf);
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	}
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	(void) close(fd);
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	if (forked)
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		_exit(0);
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	return (NULL);
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}