1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1988, 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33
34__FBSDID("$FreeBSD$");
35
36#ifndef lint
37static const char copyright[] =
38"@(#) Copyright (c) 1988, 1990, 1993\n\
39	The Regents of the University of California.  All rights reserved.\n";
40#endif
41
42#ifndef lint
43static const char sccsid[] = "@(#)wall.c	8.2 (Berkeley) 11/16/93";
44#endif
45
46/*
47 * This program is not related to David Wall, whose Stanford Ph.D. thesis
48 * is entitled "Mechanisms for Broadcast and Selective Broadcast".
49 */
50
51#include <sys/param.h>
52#include <sys/stat.h>
53#include <sys/uio.h>
54
55#include <ctype.h>
56#include <err.h>
57#include <grp.h>
58#include <locale.h>
59#include <paths.h>
60#include <pwd.h>
61#include <stdio.h>
62#include <stdlib.h>
63#include <string.h>
64#include <time.h>
65#include <unistd.h>
66#include <utmpx.h>
67#include <wchar.h>
68#include <wctype.h>
69
70#include "ttymsg.h"
71
72static void makemsg(char *);
73static void usage(void);
74
75static struct wallgroup {
76	struct wallgroup *next;
77	char		*name;
78	gid_t		gid;
79} *grouplist;
80static int nobanner;
81static int mbufsize;
82static char *mbuf;
83
84static int
85ttystat(char *line)
86{
87	struct stat sb;
88	char ttybuf[MAXPATHLEN];
89
90	(void)snprintf(ttybuf, sizeof(ttybuf), "%s%s", _PATH_DEV, line);
91	if (stat(ttybuf, &sb) == 0) {
92		return (0);
93	} else
94		return (-1);
95}
96
97int
98main(int argc, char *argv[])
99{
100	struct iovec iov;
101	struct utmpx *utmp;
102	int ch;
103	int ingroup;
104	struct wallgroup *g;
105	struct group *grp;
106	char **np;
107	const char *p;
108	struct passwd *pw;
109
110	(void)setlocale(LC_CTYPE, "");
111
112	while ((ch = getopt(argc, argv, "g:n")) != -1)
113		switch (ch) {
114		case 'n':
115			/* undoc option for shutdown: suppress banner */
116			if (geteuid() == 0)
117				nobanner = 1;
118			break;
119		case 'g':
120			g = (struct wallgroup *)malloc(sizeof *g);
121			g->next = grouplist;
122			g->name = optarg;
123			g->gid = -1;
124			grouplist = g;
125			break;
126		case '?':
127		default:
128			usage();
129		}
130	argc -= optind;
131	argv += optind;
132	if (argc > 1)
133		usage();
134
135	for (g = grouplist; g; g = g->next) {
136		grp = getgrnam(g->name);
137		if (grp != NULL)
138			g->gid = grp->gr_gid;
139		else
140			warnx("%s: no such group", g->name);
141	}
142
143	makemsg(*argv);
144
145	iov.iov_base = mbuf;
146	iov.iov_len = mbufsize;
147	/* NOSTRICT */
148	while ((utmp = getutxent()) != NULL) {
149		if (utmp->ut_type != USER_PROCESS)
150			continue;
151		if (ttystat(utmp->ut_line) != 0)
152			continue;
153		if (grouplist) {
154			ingroup = 0;
155			pw = getpwnam(utmp->ut_user);
156			if (!pw)
157				continue;
158			for (g = grouplist; g && ingroup == 0; g = g->next) {
159				if (g->gid == (gid_t)-1)
160					continue;
161				if (g->gid == pw->pw_gid)
162					ingroup = 1;
163				else if ((grp = getgrgid(g->gid)) != NULL) {
164					for (np = grp->gr_mem; *np; np++) {
165						if (strcmp(*np, utmp->ut_user) == 0) {
166							ingroup = 1;
167							break;
168						}
169					}
170				}
171			}
172			if (ingroup == 0)
173				continue;
174		}
175		if ((p = ttymsg(&iov, 1, utmp->ut_line, 60*5)) != NULL)
176			warnx("%s", p);
177	}
178	exit(0);
179}
180
181static void
182usage(void)
183{
184	(void)fprintf(stderr, "usage: wall [-g group] [file]\n");
185	exit(1);
186}
187
188void
189makemsg(char *fname)
190{
191	int cnt;
192	wchar_t ch;
193	struct tm *lt;
194	struct passwd *pw;
195	struct stat sbuf;
196	time_t now;
197	FILE *fp;
198	int fd;
199	char hostname[MAXHOSTNAMELEN], tmpname[64];
200	wchar_t *p, *tmp, lbuf[256], codebuf[13];
201	const char *tty;
202	const char *whom;
203	gid_t egid;
204
205	(void)snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
206	if ((fd = mkstemp(tmpname)) == -1 || !(fp = fdopen(fd, "r+")))
207		err(1, "can't open temporary file");
208	(void)unlink(tmpname);
209
210	if (!nobanner) {
211		tty = ttyname(STDERR_FILENO);
212		if (tty == NULL)
213			tty = "no tty";
214
215		if (!(whom = getlogin()))
216			whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
217		(void)gethostname(hostname, sizeof(hostname));
218		(void)time(&now);
219		lt = localtime(&now);
220
221		/*
222		 * all this stuff is to blank out a square for the message;
223		 * we wrap message lines at column 79, not 80, because some
224		 * terminals wrap after 79, some do not, and we can't tell.
225		 * Which means that we may leave a non-blank character
226		 * in column 80, but that can't be helped.
227		 */
228		(void)fwprintf(fp, L"\r%79s\r\n", " ");
229		(void)swprintf(lbuf, sizeof(lbuf)/sizeof(wchar_t),
230		    L"Broadcast Message from %s@%s",
231		    whom, hostname);
232		(void)fwprintf(fp, L"%-79.79S\007\007\r\n", lbuf);
233		(void)swprintf(lbuf, sizeof(lbuf)/sizeof(wchar_t),
234		    L"        (%s) at %d:%02d %s...", tty,
235		    lt->tm_hour, lt->tm_min, lt->tm_zone);
236		(void)fwprintf(fp, L"%-79.79S\r\n", lbuf);
237	}
238	(void)fwprintf(fp, L"%79s\r\n", " ");
239
240	if (fname) {
241		egid = getegid();
242		setegid(getgid());
243		if (freopen(fname, "r", stdin) == NULL)
244			err(1, "can't read %s", fname);
245		if (setegid(egid) != 0)
246			err(1, "setegid failed");
247	}
248	cnt = 0;
249	while (fgetws(lbuf, sizeof(lbuf)/sizeof(wchar_t), stdin)) {
250		for (p = lbuf; (ch = *p) != L'\0'; ++p, ++cnt) {
251			if (ch == L'\r') {
252				putwc(L'\r', fp);
253				cnt = 0;
254				continue;
255			} else if (ch == L'\n') {
256				for (; cnt < 79; ++cnt)
257					putwc(L' ', fp);
258				putwc(L'\r', fp);
259				putwc(L'\n', fp);
260				break;
261			}
262			if (cnt == 79) {
263				putwc(L'\r', fp);
264				putwc(L'\n', fp);
265				cnt = 0;
266			}
267			if (iswprint(ch) || iswspace(ch) || ch == L'\a' || ch == L'\b') {
268				putwc(ch, fp);
269			} else {
270				(void)swprintf(codebuf, sizeof(codebuf)/sizeof(wchar_t), L"<0x%X>", ch);
271				for (tmp = codebuf; *tmp != L'\0'; ++tmp) {
272					putwc(*tmp, fp);
273					if (++cnt == 79) {
274						putwc(L'\r', fp);
275						putwc(L'\n', fp);
276						cnt = 0;
277					}
278				}
279				--cnt;
280			}
281		}
282	}
283	(void)fwprintf(fp, L"%79s\r\n", " ");
284	rewind(fp);
285
286	if (fstat(fd, &sbuf))
287		err(1, "can't stat temporary file");
288	mbufsize = sbuf.st_size;
289	if (!(mbuf = malloc((u_int)mbufsize)))
290		err(1, "out of memory");
291	if ((int)fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
292		err(1, "can't read temporary file");
293	fclose(fp);
294}
295