xref: /dragonfly/usr.bin/wall/wall.c (revision 2cd2d2b5)
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  * @(#) Copyright (c) 1988, 1990, 1993 The Regents of the University of California.  All rights reserved.
34  * @(#)wall.c	8.2 (Berkeley) 11/16/93
35  * $FreeBSD: src/usr.bin/wall/wall.c,v 1.13.2.6 2001/10/18 08:08:17 des Exp $
36  * $DragonFly: src/usr.bin/wall/wall.c,v 1.3 2003/10/04 20:36:54 hmp Exp $
37  */
38 
39 /*
40  * This program is not related to David Wall, whose Stanford Ph.D. thesis
41  * is entitled "Mechanisms for Broadcast and Selective Broadcast".
42  */
43 
44 #include <sys/param.h>
45 #include <sys/stat.h>
46 #include <sys/uio.h>
47 
48 #include <ctype.h>
49 #include <err.h>
50 #include <grp.h>
51 #include <locale.h>
52 #include <paths.h>
53 #include <pwd.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <time.h>
58 #include <unistd.h>
59 #include <utmp.h>
60 
61 #include "ttymsg.h"
62 
63 static void makemsg(char *);
64 static void usage(void);
65 
66 #define	IGNOREUSER	"sleeper"
67 
68 struct wallgroup {
69 	struct wallgroup *next;
70 	char		*name;
71 	gid_t		gid;
72 } *grouplist;
73 int nobanner;
74 int mbufsize;
75 char *mbuf;
76 
77 int
78 main(int argc, char *argv[])
79 {
80 	struct iovec iov;
81 	struct utmp utmp;
82 	int ch;
83 	int ingroup;
84 	FILE *fp;
85 	struct wallgroup *g;
86 	struct group *grp;
87 	char **np;
88 	const char *p;
89 	struct passwd *pw;
90 	char line[sizeof(utmp.ut_line) + 1];
91 	char username[sizeof(utmp.ut_name) + 1];
92 
93 	(void)setlocale(LC_CTYPE, "");
94 
95 	while ((ch = getopt(argc, argv, "g:n")) != -1)
96 		switch (ch) {
97 		case 'n':
98 			/* undoc option for shutdown: suppress banner */
99 			if (geteuid() == 0)
100 				nobanner = 1;
101 			break;
102 		case 'g':
103 			g = (struct wallgroup *)malloc(sizeof *g);
104 			g->next = grouplist;
105 			g->name = optarg;
106 			g->gid = -1;
107 			grouplist = g;
108 			break;
109 		case '?':
110 		default:
111 			usage();
112 		}
113 	argc -= optind;
114 	argv += optind;
115 	if (argc > 1)
116 		usage();
117 
118 	for (g = grouplist; g; g = g->next) {
119 		grp = getgrnam(g->name);
120 		if (grp != NULL)
121 			g->gid = grp->gr_gid;
122 		else
123 			warnx("%s: no such group", g->name);
124 	}
125 
126 	makemsg(*argv);
127 
128 	if (!(fp = fopen(_PATH_UTMP, "r")))
129 		err(1, "cannot read %s", _PATH_UTMP);
130 	iov.iov_base = mbuf;
131 	iov.iov_len = mbufsize;
132 	/* NOSTRICT */
133 	while (fread((char *)&utmp, sizeof(utmp), 1, fp) == 1) {
134 		if (!utmp.ut_name[0] ||
135 		    !strncmp(utmp.ut_name, IGNOREUSER, sizeof(utmp.ut_name)))
136 			continue;
137 		if (grouplist) {
138 			ingroup = 0;
139 			strlcpy(username, utmp.ut_name, sizeof(utmp.ut_name));
140 			pw = getpwnam(username);
141 			if (!pw)
142 				continue;
143 			for (g = grouplist; g && ingroup == 0; g = g->next) {
144 				if (g->gid == -1)
145 					continue;
146 				if (g->gid == pw->pw_gid)
147 					ingroup = 1;
148 				else if ((grp = getgrgid(g->gid)) != NULL) {
149 					for (np = grp->gr_mem; *np; np++) {
150 						if (strcmp(*np, username) == 0) {
151 							ingroup = 1;
152 							break;
153 						}
154 					}
155 				}
156 			}
157 			if (ingroup == 0)
158 				continue;
159 		}
160 		strncpy(line, utmp.ut_line, sizeof(utmp.ut_line));
161 		line[sizeof(utmp.ut_line)] = '\0';
162 		if ((p = ttymsg(&iov, 1, line, 60*5)) != NULL)
163 			warnx("%s", p);
164 	}
165 	exit(0);
166 }
167 
168 static void
169 usage(void)
170 {
171 	(void)fprintf(stderr, "usage: wall [-g group] [file]\n");
172 	exit(1);
173 }
174 
175 void
176 makemsg(char *fname)
177 {
178 	int cnt;
179 	unsigned char ch;
180 	struct tm *lt;
181 	struct passwd *pw;
182 	struct stat sbuf;
183 	time_t now;
184 	FILE *fp;
185 	int fd;
186 	char *p, *tty, hostname[MAXHOSTNAMELEN], lbuf[256], tmpname[64];
187 	const char *whom;
188 	gid_t egid;
189 
190 	(void)snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
191 	if ((fd = mkstemp(tmpname)) == -1 || !(fp = fdopen(fd, "r+")))
192 		err(1, "can't open temporary file");
193 	(void)unlink(tmpname);
194 
195 	if (!nobanner) {
196 		tty = ttyname(STDERR_FILENO);
197 		if (tty == NULL)
198 			tty = "no tty";
199 
200 		if (!(whom = getlogin()))
201 			whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
202 		(void)gethostname(hostname, sizeof(hostname));
203 		(void)time(&now);
204 		lt = localtime(&now);
205 
206 		/*
207 		 * all this stuff is to blank out a square for the message;
208 		 * we wrap message lines at column 79, not 80, because some
209 		 * terminals wrap after 79, some do not, and we can't tell.
210 		 * Which means that we may leave a non-blank character
211 		 * in column 80, but that can't be helped.
212 		 */
213 		(void)fprintf(fp, "\r%79s\r\n", " ");
214 		(void)snprintf(lbuf, sizeof(lbuf),
215 		    "Broadcast Message from %s@%s",
216 		    whom, hostname);
217 		(void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf);
218 		(void)snprintf(lbuf, sizeof(lbuf),
219 		    "        (%s) at %d:%02d %s...", tty,
220 		    lt->tm_hour, lt->tm_min, lt->tm_zone);
221 		(void)fprintf(fp, "%-79.79s\r\n", lbuf);
222 	}
223 	(void)fprintf(fp, "%79s\r\n", " ");
224 
225 	if (fname) {
226 		egid = getegid();
227 		setegid(getgid());
228 	       	if (freopen(fname, "r", stdin) == NULL)
229 			err(1, "can't read %s", fname);
230 		setegid(egid);
231 	}
232 	while (fgets(lbuf, sizeof(lbuf), stdin))
233 		for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) {
234 			if (ch == '\r') {
235 				cnt = 0;
236 			} else if (cnt == 79 || ch == '\n') {
237 				for (; cnt < 79; ++cnt)
238 					putc(' ', fp);
239 				putc('\r', fp);
240 				putc('\n', fp);
241 				cnt = 0;
242 			} else if (((ch & 0x80) && ch < 0xA0) ||
243 				   /* disable upper controls */
244 				   (!isprint(ch) && !isspace(ch) &&
245 				    ch != '\a' && ch != '\b')
246 				  ) {
247 				if (ch & 0x80) {
248 					ch &= 0x7F;
249 					putc('M', fp);
250 					if (++cnt == 79) {
251 						putc('\r', fp);
252 						putc('\n', fp);
253 						cnt = 0;
254 					}
255 					putc('-', fp);
256 					if (++cnt == 79) {
257 						putc('\r', fp);
258 						putc('\n', fp);
259 						cnt = 0;
260 					}
261 				}
262 				if (iscntrl(ch)) {
263 					ch ^= 040;
264 					putc('^', fp);
265 					if (++cnt == 79) {
266 						putc('\r', fp);
267 						putc('\n', fp);
268 						cnt = 0;
269 					}
270 				}
271 				putc(ch, fp);
272 			} else {
273 				putc(ch, fp);
274 			}
275 		}
276 	(void)fprintf(fp, "%79s\r\n", " ");
277 	rewind(fp);
278 
279 	if (fstat(fd, &sbuf))
280 		err(1, "can't stat temporary file");
281 	mbufsize = sbuf.st_size;
282 	if (!(mbuf = malloc((u_int)mbufsize)))
283 		err(1, "out of memory");
284 	if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
285 		err(1, "can't read temporary file");
286 	(void)close(fd);
287 }
288