Imported from util-linux-2.2 tarball.

1 files changed, 173 insertions, 0 deletions

diff --git a/login-utils/ttymsg.c b/login-utils/ttymsg.c
new file mode 100644
index 000000000..40c178df2
--- /dev/null
+++ b/login-utils/ttymsg.c
@@ -0,0 +1,173 @@
+/*
+ * Copyright (c) 1989 The Regents of the University of California.
+ * 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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 THE REGENTS 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.
+ *
+ * Modified for Linux (which doesn\'t have snprintf()) by faith@cs.unc.edu
+ * on Sun Mar  7 16:14:18 1993.
+ *
+ */
+
+#ifndef lint
+static char sccsid[] = "@(#)ttymsg.c	5.8 (Berkeley) 7/1/91";
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <signal.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <errno.h>
+#include <paths.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+/*
+ * Display the contents of a uio structure on a terminal.  Used by wall(1)
+ * and syslogd(8).  Forks and finishes in child if write would block, waiting
+ * at most five minutes.  Returns pointer to error string on unexpected error;
+ * string is not newline-terminated.  Various "normal" errors are ignored
+ * (exclusive-use, lack of permission, etc.).
+ */
+char *
+ttymsg(iov, iovcnt, line)
+	struct iovec *iov;
+	int iovcnt;
+	char *line;
+{
+	static char device[MAXNAMLEN] = _PATH_DEV;
+	static char errbuf[1024];
+	register int cnt, fd, left, wret;
+	struct iovec localiov[6];
+	int forked = 0;
+
+	if (iovcnt > 6)
+		return ("too many iov's (change code in wall/ttymsg.c)");
+	/*
+	 * open will fail on slip lines or exclusive-use lines
+	 * if not running as root; not an error.
+	 */
+	(void) strcpy(device + sizeof(_PATH_DEV) - 1, line);
+	if ((fd = open(device, O_WRONLY|O_NONBLOCK, 0)) < 0) {
+		if (errno == EBUSY || errno == EACCES)
+			return (NULL);
+#ifdef __linux__
+		(void) sprintf(errbuf,
+		    "%s: %s", device, strerror(errno));
+#else
+		(void) snprintf(errbuf, sizeof(errbuf),
+		    "%s: %s", device, strerror(errno));
+#endif
+		return (errbuf);
+	}
+
+	for (cnt = left = 0; cnt < iovcnt; ++cnt)
+		left += iov[cnt].iov_len;
+
+	for (;;) {
+		wret = writev(fd, iov, iovcnt);
+		if (wret >= left)
+			break;
+		if (wret >= 0) {
+			left -= wret;
+			if (iov != localiov) {
+				bcopy(iov, localiov, 
+				    iovcnt * sizeof(struct iovec));
+				iov = localiov;
+			}
+			for (cnt = 0; wret >= iov->iov_len; ++cnt) {
+				wret -= iov->iov_len;
+				++iov;
+				--iovcnt;
+			}
+			if (wret) {
+				iov->iov_base += wret;
+				iov->iov_len -= wret;
+			}
+			continue;
+		}
+		if (errno == EWOULDBLOCK) {
+			int cpid, off = 0;
+
+			if (forked) {
+				(void) close(fd);
+				_exit(1);
+			}
+			cpid = fork();
+			if (cpid < 0) {
+#ifdef __linux__
+				(void) sprintf(errbuf,
+				    "fork: %s", strerror(errno));
+#else
+				(void) snprintf(errbuf, sizeof(errbuf),
+				    "fork: %s", strerror(errno));
+#endif
+				(void) close(fd);
+				return (errbuf);
+			}
+			if (cpid) {	/* parent */
+				(void) close(fd);
+				return (NULL);
+			}
+			forked++;
+			/* wait at most 5 minutes */
+			(void) signal(SIGALRM, SIG_DFL);
+			(void) signal(SIGTERM, SIG_DFL); /* XXX */
+			(void) sigsetmask(0);
+			(void) alarm((u_int)(60 * 5));
+			(void) fcntl(fd, O_NONBLOCK, &off);
+			continue;
+		} 
+		/*
+		 * We get ENODEV on a slip line if we're running as root,
+		 * and EIO if the line just went away.
+		 */
+		if (errno == ENODEV || errno == EIO)
+			break;
+		(void) close(fd);
+		if (forked)
+			_exit(1);
+#ifdef __linux__
+		(void) sprintf(errbuf,
+		    "%s: %s", device, strerror(errno));
+#else
+		(void) snprintf(errbuf, sizeof(errbuf),
+		    "%s: %s", device, strerror(errno));
+#endif
+		return (errbuf);
+	}
+
+	(void) close(fd);
+	if (forked)
+		_exit(0);
+	return (NULL);
+}