xref: /freebsd/usr.bin/wall/wall.c (revision eb6d21b4ca6d668cf89afd99eef7baeafa712197)
1 /*
2  * Copyright (c) 1988, 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 
36 __FBSDID("$FreeBSD$");
37 
38 #ifndef lint
39 static const char copyright[] =
40 "@(#) Copyright (c) 1988, 1990, 1993\n\
41 	The Regents of the University of California.  All rights reserved.\n";
42 #endif
43 
44 #ifndef lint
45 static const char sccsid[] = "@(#)wall.c	8.2 (Berkeley) 11/16/93";
46 #endif
47 
48 /*
49  * This program is not related to David Wall, whose Stanford Ph.D. thesis
50  * is entitled "Mechanisms for Broadcast and Selective Broadcast".
51  */
52 
53 #include <sys/param.h>
54 #include <sys/stat.h>
55 #include <sys/uio.h>
56 
57 #include <ctype.h>
58 #include <err.h>
59 #include <grp.h>
60 #include <locale.h>
61 #include <paths.h>
62 #include <pwd.h>
63 #include <stdio.h>
64 #include <stdlib.h>
65 #include <string.h>
66 #include <time.h>
67 #define	_ULOG_POSIX_NAMES
68 #include <ulog.h>
69 #include <unistd.h>
70 
71 #include "ttymsg.h"
72 
73 static void makemsg(char *);
74 static void usage(void);
75 
76 struct wallgroup {
77 	struct wallgroup *next;
78 	char		*name;
79 	gid_t		gid;
80 } *grouplist;
81 int nobanner;
82 int mbufsize;
83 char *mbuf;
84 
85 static int
86 ttystat(char *line)
87 {
88 	struct stat sb;
89 	char ttybuf[MAXPATHLEN];
90 
91 	(void)snprintf(ttybuf, sizeof(ttybuf), "%s%s", _PATH_DEV, line);
92 	if (stat(ttybuf, &sb) == 0) {
93 		return (0);
94 	} else
95 		return (-1);
96 }
97 
98 int
99 main(int argc, char *argv[])
100 {
101 	struct iovec iov;
102 	struct utmpx *utmp;
103 	int ch;
104 	int ingroup;
105 	struct wallgroup *g;
106 	struct group *grp;
107 	char **np;
108 	const char *p;
109 	struct passwd *pw;
110 
111 	(void)setlocale(LC_CTYPE, "");
112 
113 	while ((ch = getopt(argc, argv, "g:n")) != -1)
114 		switch (ch) {
115 		case 'n':
116 			/* undoc option for shutdown: suppress banner */
117 			if (geteuid() == 0)
118 				nobanner = 1;
119 			break;
120 		case 'g':
121 			g = (struct wallgroup *)malloc(sizeof *g);
122 			g->next = grouplist;
123 			g->name = optarg;
124 			g->gid = -1;
125 			grouplist = g;
126 			break;
127 		case '?':
128 		default:
129 			usage();
130 		}
131 	argc -= optind;
132 	argv += optind;
133 	if (argc > 1)
134 		usage();
135 
136 	for (g = grouplist; g; g = g->next) {
137 		grp = getgrnam(g->name);
138 		if (grp != NULL)
139 			g->gid = grp->gr_gid;
140 		else
141 			warnx("%s: no such group", g->name);
142 	}
143 
144 	makemsg(*argv);
145 
146 	iov.iov_base = mbuf;
147 	iov.iov_len = mbufsize;
148 	/* NOSTRICT */
149 	while ((utmp = getutxent()) != NULL) {
150 		if (utmp->ut_type != USER_PROCESS)
151 			continue;
152 		if (ttystat(utmp->ut_line) != 0)
153 			continue;
154 		if (grouplist) {
155 			ingroup = 0;
156 			pw = getpwnam(utmp->ut_user);
157 			if (!pw)
158 				continue;
159 			for (g = grouplist; g && ingroup == 0; g = g->next) {
160 				if (g->gid == (gid_t)-1)
161 					continue;
162 				if (g->gid == pw->pw_gid)
163 					ingroup = 1;
164 				else if ((grp = getgrgid(g->gid)) != NULL) {
165 					for (np = grp->gr_mem; *np; np++) {
166 						if (strcmp(*np, utmp->ut_user) == 0) {
167 							ingroup = 1;
168 							break;
169 						}
170 					}
171 				}
172 			}
173 			if (ingroup == 0)
174 				continue;
175 		}
176 		if ((p = ttymsg(&iov, 1, utmp->ut_line, 60*5)) != NULL)
177 			warnx("%s", p);
178 	}
179 	exit(0);
180 }
181 
182 static void
183 usage()
184 {
185 	(void)fprintf(stderr, "usage: wall [-g group] [file]\n");
186 	exit(1);
187 }
188 
189 void
190 makemsg(char *fname)
191 {
192 	int cnt;
193 	unsigned char ch;
194 	struct tm *lt;
195 	struct passwd *pw;
196 	struct stat sbuf;
197 	time_t now;
198 	FILE *fp;
199 	int fd;
200 	char *p, hostname[MAXHOSTNAMELEN], lbuf[256], tmpname[64];
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)fprintf(fp, "\r%79s\r\n", " ");
229 		(void)snprintf(lbuf, sizeof(lbuf),
230 		    "Broadcast Message from %s@%s",
231 		    whom, hostname);
232 		(void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf);
233 		(void)snprintf(lbuf, sizeof(lbuf),
234 		    "        (%s) at %d:%02d %s...", tty,
235 		    lt->tm_hour, lt->tm_min, lt->tm_zone);
236 		(void)fprintf(fp, "%-79.79s\r\n", lbuf);
237 	}
238 	(void)fprintf(fp, "%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 		setegid(egid);
246 	}
247 	while (fgets(lbuf, sizeof(lbuf), stdin)) {
248 		for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) {
249 			if (ch == '\r') {
250 				putc('\r', fp);
251 				cnt = 0;
252 				continue;
253 			} else if (ch == '\n') {
254 				for (; cnt < 79; ++cnt)
255 					putc(' ', fp);
256 				putc('\r', fp);
257 				putc('\n', fp);
258 				break;
259 			}
260 			if (cnt == 79) {
261 				putc('\r', fp);
262 				putc('\n', fp);
263 				cnt = 0;
264 			}
265 			if (((ch & 0x80) && ch < 0xA0) ||
266 				   /* disable upper controls */
267 				   (!isprint(ch) && !isspace(ch) &&
268 				    ch != '\a' && ch != '\b')
269 				  ) {
270 				if (ch & 0x80) {
271 					ch &= 0x7F;
272 					putc('M', fp);
273 					if (++cnt == 79) {
274 						putc('\r', fp);
275 						putc('\n', fp);
276 						cnt = 0;
277 					}
278 					putc('-', fp);
279 					if (++cnt == 79) {
280 						putc('\r', fp);
281 						putc('\n', fp);
282 						cnt = 0;
283 					}
284 				}
285 				if (iscntrl(ch)) {
286 					ch ^= 040;
287 					putc('^', fp);
288 					if (++cnt == 79) {
289 						putc('\r', fp);
290 						putc('\n', fp);
291 						cnt = 0;
292 					}
293 				}
294 			}
295 			putc(ch, fp);
296 		}
297 	}
298 	(void)fprintf(fp, "%79s\r\n", " ");
299 	rewind(fp);
300 
301 	if (fstat(fd, &sbuf))
302 		err(1, "can't stat temporary file");
303 	mbufsize = sbuf.st_size;
304 	if (!(mbuf = malloc((u_int)mbufsize)))
305 		err(1, "out of memory");
306 	if ((int)fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
307 		err(1, "can't read temporary file");
308 	(void)close(fd);
309 }
310