Adding upstream version 2.33.1.upstream/2.33.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 368 insertions, 0 deletions

diff --git a/term-utils/write.c b/term-utils/write.c
new file mode 100644
index 0000000..bd64fc2
--- /dev/null
+++ b/term-utils/write.c
@@ -0,0 +1,368 @@
+/*
+ * Copyright (c) 1989, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jef Poskanzer and Craig Leres of the Lawrence Berkeley Laboratory.
+ *
+ * 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, Mon Mar  8 18:16:24 1993, faith@cs.unc.edu
+ * Wed Jun 22 21:41:56 1994, faith@cs.unc.edu:
+ *      Added fix from Mike Grupenhoff (kashmir@umiacs.umd.edu)
+ * Mon Jul  1 17:01:39 MET DST 1996, janl@math.uio.no:
+ *      - Added fix from David.Chapell@mail.trincoll.edu enabling daemons
+ *	  to use write.
+ *      - ANSIed it since I was working on it anyway.
+ * 1999-02-22 Arkadiusz Miśkiewicz <misiek@pld.ORG.PL>
+ * - added Native Language Support
+ *
+ */
+
+#include <errno.h>
+#include <getopt.h>
+#include <paths.h>
+#include <pwd.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <time.h>
+#include <unistd.h>
+#include <utmpx.h>
+
+#include "c.h"
+#include "carefulputc.h"
+#include "closestream.h"
+#include "nls.h"
+#include "strutils.h"
+#include "ttyutils.h"
+#include "xalloc.h"
+
+static sig_atomic_t signal_received = 0;
+
+struct write_control {
+	uid_t src_uid;
+	const char *src_login;
+	const char *src_tty_path;
+	const char *src_tty_name;
+	const char *dst_login;
+	char *dst_tty_path;
+	const char *dst_tty_name;
+};
+
+static void __attribute__((__noreturn__)) usage(void)
+{
+	FILE *out = stdout;
+	fputs(USAGE_HEADER, out);
+	fprintf(out,
+	      _(" %s [options] <user> [<ttyname>]\n"),
+	      program_invocation_short_name);
+
+	fputs(USAGE_SEPARATOR, out);
+	fputs(_("Send a message to another user.\n"), out);
+
+	fputs(USAGE_OPTIONS, out);
+	printf(USAGE_HELP_OPTIONS(16));
+	printf(USAGE_MAN_TAIL("write(1)"));
+	exit(EXIT_SUCCESS);
+}
+
+/*
+ * check_tty - check that a terminal exists, and get the message bit
+ *     and the access time
+ */
+static int check_tty(const char *tty, int *tty_writeable, time_t *tty_atime, int showerror)
+{
+	struct stat s;
+
+	if (stat(tty, &s) < 0) {
+		if (showerror)
+			warn("%s", tty);
+		return 1;
+	}
+	if (getuid() == 0)	/* root can always write */
+		*tty_writeable = 1;
+	else {
+		if (getegid() != s.st_gid) {
+			warnx(_("effective gid does not match group of %s"), tty);
+			return 1;
+		}
+		*tty_writeable = s.st_mode & S_IWGRP;
+	}
+	if (tty_atime)
+		*tty_atime = s.st_atime;
+	return 0;
+}
+
+/*
+ * check_utmp - checks that the given user is actually logged in on
+ *     the given tty
+ */
+static int check_utmp(const struct write_control *ctl)
+{
+	struct utmpx *u;
+	int res = 1;
+
+	utmpxname(_PATH_UTMP);
+	setutxent();
+
+	while ((u = getutxent())) {
+		if (strncmp(ctl->dst_login, u->ut_user, sizeof(u->ut_user)) == 0 &&
+		    strncmp(ctl->dst_tty_name, u->ut_line, sizeof(u->ut_line)) == 0) {
+			res = 0;
+			break;
+		}
+	}
+
+	endutxent();
+	return res;
+}
+
+/*
+ * search_utmp - search utmp for the "best" terminal to write to
+ *
+ * Ignores terminals with messages disabled, and of the rest, returns
+ * the one with the most recent access time.  Returns as value the number
+ * of the user's terminals with messages enabled, or -1 if the user is
+ * not logged in at all.
+ *
+ * Special case for writing to yourself - ignore the terminal you're
+ * writing from, unless that's the only terminal with messages enabled.
+ */
+static void search_utmp(struct write_control *ctl)
+{
+	struct utmpx *u;
+	time_t best_atime = 0, tty_atime;
+	int num_ttys = 0, valid_ttys = 0, tty_writeable = 0, user_is_me = 0;
+	char path[sizeof(u->ut_line) + 6];
+
+	utmpxname(_PATH_UTMP);
+	setutxent();
+
+	while ((u = getutxent())) {
+		if (strncmp(ctl->dst_login, u->ut_user, sizeof(u->ut_user)) != 0)
+			continue;
+		num_ttys++;
+		sprintf(path, "/dev/%s", u->ut_line);
+		if (check_tty(path, &tty_writeable, &tty_atime, 0))
+			/* bad term? skip */
+			continue;
+		if (ctl->src_uid && !tty_writeable)
+			/* skip ttys with msgs off */
+			continue;
+		if (strcmp(u->ut_line, ctl->src_tty_name) == 0) {
+			user_is_me = 1;
+			/* don't write to yourself */
+			continue;
+		}
+		if (u->ut_type != USER_PROCESS)
+			/* it's not a valid entry */
+			continue;
+		valid_ttys++;
+		if (best_atime < tty_atime) {
+			best_atime = tty_atime;
+			free(ctl->dst_tty_path);
+			ctl->dst_tty_path = xstrdup(path);
+			ctl->dst_tty_name = ctl->dst_tty_path + 5;
+		}
+	}
+
+	endutxent();
+	if (num_ttys == 0)
+		errx(EXIT_FAILURE, _("%s is not logged in"), ctl->dst_login);
+	if (valid_ttys == 0) {
+		if (user_is_me) {
+			/* ok, so write to yourself! */
+			if (!ctl->src_tty_path)
+				errx(EXIT_FAILURE, _("can't find your tty's name"));
+			ctl->dst_tty_path = xstrdup(ctl->src_tty_path);
+			ctl->dst_tty_name = ctl->dst_tty_path + 5;
+			return;
+		}
+		errx(EXIT_FAILURE, _("%s has messages disabled"), ctl->dst_login);
+	}
+	if (1 < valid_ttys)
+		warnx(_("%s is logged in more than once; writing to %s"),
+		      ctl->dst_login, ctl->dst_tty_name);
+}
+
+/*
+ * signal_handler - cause write loop to exit
+ */
+static void signal_handler(int signo)
+{
+	signal_received = signo;
+}
+
+/*
+ * write_line - like fputs(), but makes control characters visible and
+ *     turns \n into \r\n.
+ */
+static void write_line(char *s)
+{
+	while (*s) {
+		const int c = *s++;
+
+		if ((c == '\n' && fputc_careful('\r', stdout, '^') == EOF)
+		    || fputc_careful(c, stdout, '^') == EOF)
+			err(EXIT_FAILURE, _("carefulputc failed"));
+	}
+}
+
+/*
+ * do_write - actually make the connection
+ */
+static void do_write(const struct write_control *ctl)
+{
+	char *login, *pwuid;
+	struct passwd *pwd;
+	time_t now;
+	struct tm *tm;
+	char *host, line[512];
+	struct sigaction sigact;
+
+	/* Determine our login name(s) before the we reopen() stdout */
+	if ((pwd = getpwuid(ctl->src_uid)) != NULL)
+		pwuid = pwd->pw_name;
+	else
+		pwuid = "???";
+	if ((login = getlogin()) == NULL)
+		login = pwuid;
+
+	if ((freopen(ctl->dst_tty_path, "w", stdout)) == NULL)
+		err(EXIT_FAILURE, "%s", ctl->dst_tty_path);
+
+	sigact.sa_handler = signal_handler;
+	sigemptyset(&sigact.sa_mask);
+	sigact.sa_flags = 0;
+	sigaction(SIGINT, &sigact, NULL);
+	sigaction(SIGHUP, &sigact, NULL);
+
+	host = xgethostname();
+	if (!host)
+		host = xstrdup("???");
+
+	now = time((time_t *)NULL);
+	tm = localtime(&now);
+	/* print greeting */
+	printf("\r\n\a\a\a");
+	if (strcmp(login, pwuid))
+		printf(_("Message from %s@%s (as %s) on %s at %02d:%02d ..."),
+		       login, host, pwuid, ctl->src_tty_name,
+		       tm->tm_hour, tm->tm_min);
+	else
+		printf(_("Message from %s@%s on %s at %02d:%02d ..."),
+		       login, host, ctl->src_tty_name,
+		       tm->tm_hour, tm->tm_min);
+	free(host);
+	printf("\r\n");
+
+	while (fgets(line, sizeof(line), stdin) != NULL) {
+		if (signal_received)
+			break;
+		write_line(line);
+	}
+	printf("EOF\r\n");
+}
+
+int main(int argc, char **argv)
+{
+	int tty_writeable = 0, c;
+	struct write_control ctl = { 0 };
+
+	static const struct option longopts[] = {
+		{"version", no_argument, NULL, 'V'},
+		{"help", no_argument, NULL, 'h'},
+		{NULL, 0, NULL, 0}
+	};
+
+	setlocale(LC_ALL, "");
+	bindtextdomain(PACKAGE, LOCALEDIR);
+	textdomain(PACKAGE);
+	atexit(close_stdout);
+
+	while ((c = getopt_long(argc, argv, "Vh", longopts, NULL)) != -1)
+		switch (c) {
+		case 'V':
+			printf(UTIL_LINUX_VERSION);
+			return EXIT_SUCCESS;
+		case 'h':
+			usage();
+		default:
+			errtryhelp(EXIT_FAILURE);
+		}
+
+	if (get_terminal_name(&ctl.src_tty_path, &ctl.src_tty_name, NULL) == 0) {
+		/* check that sender has write enabled */
+		if (check_tty(ctl.src_tty_path, &tty_writeable, NULL, 1))
+			exit(EXIT_FAILURE);
+		if (!tty_writeable)
+			errx(EXIT_FAILURE,
+			     _("you have write permission turned off"));
+		tty_writeable = 0;
+	} else
+		ctl.src_tty_name = "<no tty>";
+
+	ctl.src_uid = getuid();
+
+	/* check args */
+	switch (argc) {
+	case 2:
+		ctl.dst_login = argv[1];
+		search_utmp(&ctl);
+		do_write(&ctl);
+		break;
+	case 3:
+		ctl.dst_login = argv[1];
+		if (!strncmp(argv[2], "/dev/", 5))
+			ctl.dst_tty_path = xstrdup(argv[2]);
+		else
+			xasprintf(&ctl.dst_tty_path, "/dev/%s", argv[2]);
+		ctl.dst_tty_name = ctl.dst_tty_path + 5;
+		if (check_utmp(&ctl))
+			errx(EXIT_FAILURE,
+			     _("%s is not logged in on %s"),
+			     ctl.dst_login, ctl.dst_tty_name);
+		if (check_tty(ctl.dst_tty_path, &tty_writeable, NULL, 1))
+			exit(EXIT_FAILURE);
+		if (ctl.src_uid && !tty_writeable)
+			errx(EXIT_FAILURE,
+			     _("%s has messages disabled on %s"),
+			     ctl.dst_login, ctl.dst_tty_name);
+		do_write(&ctl);
+		break;
+	default:
+		errtryhelp(EXIT_FAILURE);
+	}
+	free(ctl.dst_tty_path);
+	return EXIT_SUCCESS;
+}