xref: /freebsd/usr.bin/wall/wall.c (revision 7431dfd4580e850375fe5478d92ec770344db098)
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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 
32 __FBSDID("$FreeBSD$");
33 
34 #ifndef lint
35 static const char copyright[] =
36 "@(#) Copyright (c) 1988, 1990, 1993\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif
39 
40 #ifndef lint
41 static const char sccsid[] = "@(#)wall.c	8.2 (Berkeley) 11/16/93";
42 #endif
43 
44 /*
45  * This program is not related to David Wall, whose Stanford Ph.D. thesis
46  * is entitled "Mechanisms for Broadcast and Selective Broadcast".
47  */
48 
49 #include <sys/param.h>
50 #include <sys/stat.h>
51 #include <sys/uio.h>
52 
53 #include <ctype.h>
54 #include <err.h>
55 #include <grp.h>
56 #include <locale.h>
57 #include <paths.h>
58 #include <pwd.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <time.h>
63 #include <unistd.h>
64 #include <utmpx.h>
65 #include <wchar.h>
66 #include <wctype.h>
67 
68 #include "ttymsg.h"
69 
70 static void makemsg(char *);
71 static void usage(void);
72 
73 static struct wallgroup {
74 	struct wallgroup *next;
75 	char		*name;
76 	gid_t		gid;
77 } *grouplist;
78 static int nobanner;
79 static int mbufsize;
80 static char *mbuf;
81 
82 static int
83 ttystat(char *line)
84 {
85 	struct stat sb;
86 	char ttybuf[MAXPATHLEN];
87 
88 	(void)snprintf(ttybuf, sizeof(ttybuf), "%s%s", _PATH_DEV, line);
89 	if (stat(ttybuf, &sb) == 0) {
90 		return (0);
91 	} else
92 		return (-1);
93 }
94 
95 int
96 main(int argc, char *argv[])
97 {
98 	struct iovec iov;
99 	struct utmpx *utmp;
100 	int ch;
101 	int ingroup;
102 	struct wallgroup *g;
103 	struct group *grp;
104 	char **np;
105 	const char *p;
106 	struct passwd *pw;
107 
108 	(void)setlocale(LC_CTYPE, "");
109 
110 	while ((ch = getopt(argc, argv, "g:n")) != -1)
111 		switch (ch) {
112 		case 'n':
113 			/* undoc option for shutdown: suppress banner */
114 			if (geteuid() == 0)
115 				nobanner = 1;
116 			break;
117 		case 'g':
118 			g = (struct wallgroup *)malloc(sizeof *g);
119 			g->next = grouplist;
120 			g->name = optarg;
121 			g->gid = -1;
122 			grouplist = g;
123 			break;
124 		case '?':
125 		default:
126 			usage();
127 		}
128 	argc -= optind;
129 	argv += optind;
130 	if (argc > 1)
131 		usage();
132 
133 	for (g = grouplist; g; g = g->next) {
134 		grp = getgrnam(g->name);
135 		if (grp != NULL)
136 			g->gid = grp->gr_gid;
137 		else
138 			warnx("%s: no such group", g->name);
139 	}
140 
141 	makemsg(*argv);
142 
143 	iov.iov_base = mbuf;
144 	iov.iov_len = mbufsize;
145 	/* NOSTRICT */
146 	while ((utmp = getutxent()) != NULL) {
147 		if (utmp->ut_type != USER_PROCESS)
148 			continue;
149 		if (ttystat(utmp->ut_line) != 0)
150 			continue;
151 		if (grouplist) {
152 			ingroup = 0;
153 			pw = getpwnam(utmp->ut_user);
154 			if (!pw)
155 				continue;
156 			for (g = grouplist; g && ingroup == 0; g = g->next) {
157 				if (g->gid == (gid_t)-1)
158 					continue;
159 				if (g->gid == pw->pw_gid)
160 					ingroup = 1;
161 				else if ((grp = getgrgid(g->gid)) != NULL) {
162 					for (np = grp->gr_mem; *np; np++) {
163 						if (strcmp(*np, utmp->ut_user) == 0) {
164 							ingroup = 1;
165 							break;
166 						}
167 					}
168 				}
169 			}
170 			if (ingroup == 0)
171 				continue;
172 		}
173 		if ((p = ttymsg(&iov, 1, utmp->ut_line, 60*5)) != NULL)
174 			warnx("%s", p);
175 	}
176 	exit(0);
177 }
178 
179 static void
180 usage(void)
181 {
182 	(void)fprintf(stderr, "usage: wall [-g group] [file]\n");
183 	exit(1);
184 }
185 
186 void
187 makemsg(char *fname)
188 {
189 	int cnt;
190 	wchar_t ch;
191 	struct tm *lt;
192 	struct passwd *pw;
193 	struct stat sbuf;
194 	time_t now;
195 	FILE *fp;
196 	int fd;
197 	char hostname[MAXHOSTNAMELEN], tmpname[64];
198 	wchar_t *p, *tmp, lbuf[256], codebuf[13];
199 	const char *tty;
200 	const char *whom;
201 	gid_t egid;
202 
203 	(void)snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
204 	if ((fd = mkstemp(tmpname)) == -1 || !(fp = fdopen(fd, "r+")))
205 		err(1, "can't open temporary file");
206 	(void)unlink(tmpname);
207 
208 	if (!nobanner) {
209 		tty = ttyname(STDERR_FILENO);
210 		if (tty == NULL)
211 			tty = "no tty";
212 
213 		if (!(whom = getlogin()))
214 			whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
215 		(void)gethostname(hostname, sizeof(hostname));
216 		(void)time(&now);
217 		lt = localtime(&now);
218 
219 		/*
220 		 * all this stuff is to blank out a square for the message;
221 		 * we wrap message lines at column 79, not 80, because some
222 		 * terminals wrap after 79, some do not, and we can't tell.
223 		 * Which means that we may leave a non-blank character
224 		 * in column 80, but that can't be helped.
225 		 */
226 		(void)fwprintf(fp, L"\r%79s\r\n", " ");
227 		(void)swprintf(lbuf, sizeof(lbuf)/sizeof(wchar_t),
228 		    L"Broadcast Message from %s@%s",
229 		    whom, hostname);
230 		(void)fwprintf(fp, L"%-79.79S\007\007\r\n", lbuf);
231 		(void)swprintf(lbuf, sizeof(lbuf)/sizeof(wchar_t),
232 		    L"        (%s) at %d:%02d %s...", tty,
233 		    lt->tm_hour, lt->tm_min, lt->tm_zone);
234 		(void)fwprintf(fp, L"%-79.79S\r\n", lbuf);
235 	}
236 	(void)fwprintf(fp, L"%79s\r\n", " ");
237 
238 	if (fname) {
239 		egid = getegid();
240 		setegid(getgid());
241 		if (freopen(fname, "r", stdin) == NULL)
242 			err(1, "can't read %s", fname);
243 		if (setegid(egid) != 0)
244 			err(1, "setegid failed");
245 	}
246 	cnt = 0;
247 	while (fgetws(lbuf, sizeof(lbuf)/sizeof(wchar_t), stdin)) {
248 		for (p = lbuf; (ch = *p) != L'\0'; ++p, ++cnt) {
249 			if (ch == L'\r') {
250 				putwc(L'\r', fp);
251 				cnt = 0;
252 				continue;
253 			} else if (ch == L'\n') {
254 				for (; cnt < 79; ++cnt)
255 					putwc(L' ', fp);
256 				putwc(L'\r', fp);
257 				putwc(L'\n', fp);
258 				break;
259 			}
260 			if (cnt == 79) {
261 				putwc(L'\r', fp);
262 				putwc(L'\n', fp);
263 				cnt = 0;
264 			}
265 			if (iswprint(ch) || iswspace(ch) || ch == L'\a' || ch == L'\b') {
266 				putwc(ch, fp);
267 			} else {
268 				(void)swprintf(codebuf, sizeof(codebuf)/sizeof(wchar_t), L"<0x%X>", ch);
269 				for (tmp = codebuf; *tmp != L'\0'; ++tmp) {
270 					putwc(*tmp, fp);
271 					if (++cnt == 79) {
272 						putwc(L'\r', fp);
273 						putwc(L'\n', fp);
274 						cnt = 0;
275 					}
276 				}
277 				--cnt;
278 			}
279 		}
280 	}
281 	(void)fwprintf(fp, L"%79s\r\n", " ");
282 	rewind(fp);
283 
284 	if (fstat(fd, &sbuf))
285 		err(1, "can't stat temporary file");
286 	mbufsize = sbuf.st_size;
287 	if (!(mbuf = malloc((u_int)mbufsize)))
288 		err(1, "out of memory");
289 	if ((int)fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
290 		err(1, "can't read temporary file");
291 	(void)close(fd);
292 }
293