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/*
33 * This program is not related to David Wall, whose Stanford Ph.D. thesis
34 * is entitled "Mechanisms for Broadcast and Selective Broadcast".
35 */
36
37#include <sys/param.h>
38#include <sys/stat.h>
39#include <sys/uio.h>
40
41#include <ctype.h>
42#include <err.h>
43#include <grp.h>
44#include <locale.h>
45#include <paths.h>
46#include <pwd.h>
47#include <stdio.h>
48#include <stdlib.h>
49#include <string.h>
50#include <time.h>
51#include <unistd.h>
52#include <utmpx.h>
53#include <wchar.h>
54#include <wctype.h>
55
56#include "ttymsg.h"
57
58static void makemsg(char *);
59static void usage(void) __dead2;
60
61static struct wallgroup {
62	struct wallgroup *next;
63	char		*name;
64	gid_t		gid;
65} *grouplist;
66static int nobanner;
67static int mbufsize;
68static char *mbuf;
69
70static int
71ttystat(char *line)
72{
73	struct stat sb;
74	char ttybuf[MAXPATHLEN];
75
76	(void)snprintf(ttybuf, sizeof(ttybuf), "%s%s", _PATH_DEV, line);
77	if (stat(ttybuf, &sb) == 0) {
78		return (0);
79	} else
80		return (-1);
81}
82
83int
84main(int argc, char *argv[])
85{
86	struct iovec iov;
87	struct utmpx *utmp;
88	int ch;
89	int ingroup;
90	struct wallgroup *g;
91	struct group *grp;
92	char **np;
93	const char *p;
94	struct passwd *pw;
95
96	(void)setlocale(LC_CTYPE, "");
97
98	while ((ch = getopt(argc, argv, "g:n")) != -1)
99		switch (ch) {
100		case 'n':
101			/* undoc option for shutdown: suppress banner */
102			if (geteuid() == 0)
103				nobanner = 1;
104			break;
105		case 'g':
106			g = (struct wallgroup *)malloc(sizeof *g);
107			g->next = grouplist;
108			g->name = optarg;
109			g->gid = -1;
110			grouplist = g;
111			break;
112		case '?':
113		default:
114			usage();
115		}
116	argc -= optind;
117	argv += optind;
118	if (argc > 1)
119		usage();
120
121	for (g = grouplist; g; g = g->next) {
122		grp = getgrnam(g->name);
123		if (grp != NULL)
124			g->gid = grp->gr_gid;
125		else
126			warnx("%s: no such group", g->name);
127	}
128
129	makemsg(*argv);
130
131	iov.iov_base = mbuf;
132	iov.iov_len = mbufsize;
133	/* NOSTRICT */
134	while ((utmp = getutxent()) != NULL) {
135		if (utmp->ut_type != USER_PROCESS)
136			continue;
137		if (ttystat(utmp->ut_line) != 0)
138			continue;
139		if (grouplist) {
140			ingroup = 0;
141			pw = getpwnam(utmp->ut_user);
142			if (!pw)
143				continue;
144			for (g = grouplist; g && ingroup == 0; g = g->next) {
145				if (g->gid == (gid_t)-1)
146					continue;
147				if (g->gid == pw->pw_gid)
148					ingroup = 1;
149				else if ((grp = getgrgid(g->gid)) != NULL) {
150					for (np = grp->gr_mem; *np; np++) {
151						if (strcmp(*np, utmp->ut_user) == 0) {
152							ingroup = 1;
153							break;
154						}
155					}
156				}
157			}
158			if (ingroup == 0)
159				continue;
160		}
161		if ((p = ttymsg(&iov, 1, utmp->ut_line, 60*5)) != NULL)
162			warnx("%s", p);
163	}
164	exit(0);
165}
166
167static void
168usage(void)
169{
170	(void)fprintf(stderr, "usage: wall [-g group] [file]\n");
171	exit(1);
172}
173
174void
175makemsg(char *fname)
176{
177	int cnt;
178	wchar_t ch;
179	struct tm *lt;
180	struct passwd *pw;
181	struct stat sbuf;
182	time_t now;
183	FILE *fp;
184	int fd;
185	char hostname[MAXHOSTNAMELEN], tmpname[64];
186	wchar_t *p, *tmp, lbuf[256], codebuf[13];
187	const char *tty;
188	const char *whom;
189	gid_t egid;
190
191	(void)snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
192	if ((fd = mkstemp(tmpname)) == -1 || !(fp = fdopen(fd, "r+")))
193		err(1, "can't open temporary file");
194	(void)unlink(tmpname);
195
196	if (!nobanner) {
197		tty = ttyname(STDERR_FILENO);
198		if (tty == NULL)
199			tty = "no tty";
200
201		if (!(whom = getlogin()))
202			whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
203		(void)gethostname(hostname, sizeof(hostname));
204		(void)time(&now);
205		lt = localtime(&now);
206
207		/*
208		 * all this stuff is to blank out a square for the message;
209		 * we wrap message lines at column 79, not 80, because some
210		 * terminals wrap after 79, some do not, and we can't tell.
211		 * Which means that we may leave a non-blank character
212		 * in column 80, but that can't be helped.
213		 */
214		(void)fwprintf(fp, L"\r%79s\r\n", " ");
215		(void)swprintf(lbuf, sizeof(lbuf)/sizeof(wchar_t),
216		    L"Broadcast Message from %s@%s",
217		    whom, hostname);
218		(void)fwprintf(fp, L"%-79.79S\007\007\r\n", lbuf);
219		(void)swprintf(lbuf, sizeof(lbuf)/sizeof(wchar_t),
220		    L"        (%s) at %d:%02d %s...", tty,
221		    lt->tm_hour, lt->tm_min, lt->tm_zone);
222		(void)fwprintf(fp, L"%-79.79S\r\n", lbuf);
223	}
224	(void)fwprintf(fp, L"%79s\r\n", " ");
225
226	if (fname) {
227		egid = getegid();
228		setegid(getgid());
229		if (freopen(fname, "r", stdin) == NULL)
230			err(1, "can't read %s", fname);
231		if (setegid(egid) != 0)
232			err(1, "setegid failed");
233	}
234	cnt = 0;
235	while (fgetws(lbuf, sizeof(lbuf)/sizeof(wchar_t), stdin)) {
236		for (p = lbuf; (ch = *p) != L'\0'; ++p, ++cnt) {
237			if (ch == L'\r') {
238				putwc(L'\r', fp);
239				cnt = 0;
240				continue;
241			} else if (ch == L'\n') {
242				for (; cnt < 79; ++cnt)
243					putwc(L' ', fp);
244				putwc(L'\r', fp);
245				putwc(L'\n', fp);
246				break;
247			}
248			if (cnt == 79) {
249				putwc(L'\r', fp);
250				putwc(L'\n', fp);
251				cnt = 0;
252			}
253			if (iswprint(ch) || iswspace(ch) || ch == L'\a' || ch == L'\b') {
254				putwc(ch, fp);
255			} else {
256				(void)swprintf(codebuf, sizeof(codebuf)/sizeof(wchar_t), L"<0x%X>", ch);
257				for (tmp = codebuf; *tmp != L'\0'; ++tmp) {
258					putwc(*tmp, fp);
259					if (++cnt == 79) {
260						putwc(L'\r', fp);
261						putwc(L'\n', fp);
262						cnt = 0;
263					}
264				}
265				--cnt;
266			}
267		}
268	}
269	(void)fwprintf(fp, L"%79s\r\n", " ");
270	rewind(fp);
271
272	if (fstat(fd, &sbuf))
273		err(1, "can't stat temporary file");
274	mbufsize = sbuf.st_size;
275	if (!(mbuf = malloc((u_int)mbufsize)))
276		err(1, "out of memory");
277	if ((int)fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
278		err(1, "can't read temporary file");
279	fclose(fp);
280}
281