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
58 static void makemsg(char *);
59 static void usage(void) __dead2;
60
61 static struct wallgroup {
62 struct wallgroup *next;
63 char *name;
64 gid_t gid;
65 } *grouplist;
66 static int nobanner;
67 static int mbufsize;
68 static char *mbuf;
69
70 static int
ttystat(char * line)71 ttystat(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
83 int
main(int argc,char * argv[])84 main(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
167 static void
usage(void)168 usage(void)
169 {
170 (void)fprintf(stderr, "usage: wall [-g group] [file]\n");
171 exit(1);
172 }
173
174 void
makemsg(char * fname)175 makemsg(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