Annotation of src/usr.bin/wall/wall.c, Revision 1.37
1.37 ! guenther 1: /* $OpenBSD: wall.c,v 1.36 2022/05/05 10:04:24 bluhm Exp $ */
1.1 deraadt 2: /* $NetBSD: wall.c,v 1.6 1994/11/17 07:17:58 jtc Exp $ */
3:
4: /*
5: * Copyright (c) 1988, 1990, 1993
6: * The Regents of the University of California. All rights reserved.
7: *
8: * Redistribution and use in source and binary forms, with or without
9: * modification, are permitted provided that the following conditions
10: * are met:
11: * 1. Redistributions of source code must retain the above copyright
12: * notice, this list of conditions and the following disclaimer.
13: * 2. Redistributions in binary form must reproduce the above copyright
14: * notice, this list of conditions and the following disclaimer in the
15: * documentation and/or other materials provided with the distribution.
1.18 millert 16: * 3. Neither the name of the University nor the names of its contributors
1.1 deraadt 17: * may be used to endorse or promote products derived from this software
18: * without specific prior written permission.
19: *
20: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30: * SUCH DAMAGE.
31: */
32:
33: /*
34: * This program is not related to David Wall, whose Stanford Ph.D. thesis
35: * is entitled "Mechanisms for Broadcast and Selective Broadcast".
36: */
37:
1.29 benno 38: #include <sys/queue.h>
1.1 deraadt 39: #include <sys/stat.h>
40: #include <sys/time.h>
41: #include <sys/uio.h>
42:
1.30 martijn 43: #include <ctype.h>
44: #include <err.h>
45: #include <grp.h>
46: #include <limits.h>
1.1 deraadt 47: #include <paths.h>
48: #include <pwd.h>
49: #include <stdio.h>
50: #include <stdlib.h>
51: #include <string.h>
52: #include <unistd.h>
53: #include <utmp.h>
54:
1.6 deraadt 55: struct wallgroup {
1.15 millert 56: gid_t gid;
57: char *name;
58: char **mem;
1.6 deraadt 59: struct wallgroup *next;
60: } *grouplist;
61:
1.29 benno 62: struct utmptty {
63: char *tty;
64: SLIST_ENTRY(utmptty) next;
65: };
66:
1.15 millert 67: void makemsg(char *);
68: void addgroup(struct group *, char *);
69: char *ttymsg(struct iovec *, int, char *, int);
70: __dead void usage(void);
1.30 martijn 71: static int isu8cont(unsigned char);
1.1 deraadt 72:
73: int nobanner;
74: int mbufsize;
75: char *mbuf;
76:
77: int
1.15 millert 78: main(int argc, char **argv)
1.1 deraadt 79: {
1.15 millert 80: FILE *fp;
81: int ch, ingroup;
1.1 deraadt 82: struct iovec iov;
83: struct utmp utmp;
1.15 millert 84: char *p, **mem;
1.1 deraadt 85: char line[sizeof(utmp.ut_line) + 1];
1.15 millert 86: char username[sizeof(utmp.ut_name) + 1];
87: struct passwd *pw;
88: struct group *grp;
1.6 deraadt 89: struct wallgroup *g;
1.29 benno 90: struct utmptty *un;
91: SLIST_HEAD(,utmptty) utmphead;
92: SLIST_INIT(&utmphead);
1.1 deraadt 93:
1.8 millert 94: while ((ch = getopt(argc, argv, "ng:")) != -1)
1.1 deraadt 95: switch (ch) {
96: case 'n':
97: /* undoc option for shutdown: suppress banner */
1.15 millert 98: pw = getpwnam("nobody");
99: if (geteuid() == 0 || (pw && getuid() == pw->pw_uid))
1.1 deraadt 100: nobanner = 1;
101: break;
1.6 deraadt 102: case 'g':
1.15 millert 103: if ((grp = getgrnam(optarg)) == NULL)
104: errx(1, "unknown group `%s'", optarg);
105: addgroup(grp, optarg);
1.6 deraadt 106: break;
1.1 deraadt 107: default:
1.15 millert 108: usage();
1.1 deraadt 109: }
110: argc -= optind;
111: argv += optind;
112: if (argc > 1)
1.15 millert 113: usage();
1.6 deraadt 114:
1.1 deraadt 115: makemsg(*argv);
116:
1.33 deraadt 117: if (unveil(_PATH_UTMP, "r") == -1)
1.35 beck 118: err(1, "unveil %s", _PATH_UTMP);
1.33 deraadt 119: if (unveil(_PATH_DEV, "w") == -1)
1.35 beck 120: err(1, "unveil %s", _PATH_DEV);
1.34 deraadt 121: if (unveil(_PATH_DEVDB, "r") == -1)
1.35 beck 122: err(1, "unveil %s", _PATH_DEVDB);
1.29 benno 123: if (pledge("stdio rpath wpath getpw proc", NULL) == -1)
124: err(1, "pledge");
125:
1.9 form 126: if (!(fp = fopen(_PATH_UTMP, "r")))
1.21 henning 127: err(1, "cannot read %s", _PATH_UTMP);
1.1 deraadt 128: iov.iov_base = mbuf;
129: iov.iov_len = mbufsize;
1.29 benno 130:
1.15 millert 131: while (fread(&utmp, sizeof(utmp), 1, fp) == 1) {
1.16 deraadt 132: if (!utmp.ut_name[0])
1.1 deraadt 133: continue;
1.6 deraadt 134: if (grouplist) {
1.15 millert 135: ingroup = 0;
136: strncpy(username, utmp.ut_name, sizeof(utmp.ut_name));
137: username[sizeof(utmp.ut_name)] = '\0';
1.6 deraadt 138: pw = getpwnam(username);
139: if (!pw)
140: continue;
141: for (g = grouplist; g && ingroup == 0; g = g->next) {
142: if (g->gid == pw->pw_gid)
143: ingroup = 1;
1.15 millert 144: for (mem = g->mem; *mem && ingroup == 0; mem++)
145: if (strcmp(username, *mem) == 0)
1.6 deraadt 146: ingroup = 1;
147: }
148: if (ingroup == 0)
149: continue;
150: }
1.1 deraadt 151: strncpy(line, utmp.ut_line, sizeof(utmp.ut_line));
152: line[sizeof(utmp.ut_line)] = '\0';
1.29 benno 153: un = malloc(sizeof(struct utmptty));
154: if (un == NULL)
155: err(1, "malloc");
156: un->tty = strndup(line, sizeof(utmp.ut_line));
157: if (un->tty == NULL)
158: err(1, "strndup");
159: SLIST_INSERT_HEAD(&utmphead, un, next);
160: }
161: fclose(fp);
162:
163: if (pledge("stdio rpath wpath proc", NULL) == -1)
164: err(1, "pledge");
165:
166: SLIST_FOREACH(un, &utmphead, next) {
167: if ((p = ttymsg(&iov, 1, un->tty, 60*5)) != NULL)
1.13 deraadt 168: warnx("%s", p);
1.1 deraadt 169: }
1.29 benno 170:
1.1 deraadt 171: exit(0);
172: }
173:
174: void
1.15 millert 175: makemsg(char *fname)
1.1 deraadt 176: {
1.30 martijn 177: int cnt;
1.1 deraadt 178: struct tm *lt;
179: struct passwd *pw;
180: struct stat sbuf;
1.19 deraadt 181: time_t now;
1.1 deraadt 182: FILE *fp;
183: int fd;
1.26 deraadt 184: char *p, *whom, hostname[HOST_NAME_MAX+1], lbuf[100], tmpname[PATH_MAX];
1.11 d 185: char *ttynam;
1.30 martijn 186: unsigned char ch;
1.1 deraadt 187:
1.20 avsm 188: snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXXXXXX", _PATH_TMP);
1.15 millert 189: if ((fd = mkstemp(tmpname)) >= 0) {
190: (void)unlink(tmpname);
191: fp = fdopen(fd, "r+");
192: }
193: if (fd == -1 || fp == NULL)
1.21 henning 194: err(1, "can't open temporary file");
1.1 deraadt 195:
196: if (!nobanner) {
197: if (!(whom = getlogin()))
198: whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
199: (void)gethostname(hostname, sizeof(hostname));
200: (void)time(&now);
201: lt = localtime(&now);
1.11 d 202: if ((ttynam = ttyname(STDERR_FILENO)) == NULL)
203: ttynam = "(not a tty)";
1.1 deraadt 204:
205: /*
206: * all this stuff is to blank out a square for the message;
207: * we wrap message lines at column 79, not 80, because some
208: * terminals wrap after 79, some do not, and we can't tell.
209: * Which means that we may leave a non-blank character
210: * in column 80, but that can't be helped.
211: */
212: (void)fprintf(fp, "\r%79s\r\n", " ");
1.3 deraadt 213: (void)snprintf(lbuf, sizeof lbuf,
214: "Broadcast Message from %s@%s", whom, hostname);
1.1 deraadt 215: (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf);
1.3 deraadt 216: (void)snprintf(lbuf, sizeof lbuf,
1.11 d 217: " (%s) at %d:%02d ...", ttynam,
1.1 deraadt 218: lt->tm_hour, lt->tm_min);
219: (void)fprintf(fp, "%-79.79s\r\n", lbuf);
220: }
221: (void)fprintf(fp, "%79s\r\n", " ");
222:
1.13 deraadt 223: if (fname) {
224: gid_t egid = getegid();
225:
226: setegid(getgid());
227: if (freopen(fname, "r", stdin) == NULL)
1.21 henning 228: err(1, "can't read %s", fname);
1.13 deraadt 229: setegid(egid);
230: }
1.36 bluhm 231: cnt = 0;
1.1 deraadt 232: while (fgets(lbuf, sizeof(lbuf), stdin))
1.36 bluhm 233: for (p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) {
1.30 martijn 234: if (cnt == 79 || ch == '\n') {
235: for (; cnt < 79; ++cnt)
1.1 deraadt 236: putc(' ', fp);
237: putc('\r', fp);
238: putc('\n', fp);
239: cnt = -1;
1.36 bluhm 240: if (ch != '\n')
241: p--;
1.30 martijn 242: } else if (!isu8cont(ch))
1.32 martijn 243: putc(isprint(ch) || isspace(ch) || ch == '\a' ?
1.30 martijn 244: ch : '?', fp);
1.1 deraadt 245: }
246: (void)fprintf(fp, "%79s\r\n", " ");
247: rewind(fp);
248:
1.9 form 249: if (fstat(fd, &sbuf))
1.21 henning 250: err(1, "can't stat temporary file");
1.1 deraadt 251: mbufsize = sbuf.st_size;
1.22 tom 252: mbuf = malloc((u_int)mbufsize);
253: if (mbuf == NULL)
254: err(1, NULL);
1.9 form 255: if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
1.21 henning 256: err(1, "can't read temporary file");
1.1 deraadt 257: (void)close(fd);
1.15 millert 258: }
259:
260: void
261: addgroup(struct group *grp, char *name)
262: {
263: int i;
264: struct wallgroup *g;
265:
266: for (i = 0; grp->gr_mem[i]; i++)
267: ;
268:
1.27 deraadt 269: g = malloc(sizeof *g);
1.15 millert 270: if (g == NULL)
1.22 tom 271: err(1, NULL);
1.15 millert 272: g->gid = grp->gr_gid;
273: g->name = name;
1.27 deraadt 274: g->mem = calloc(i + 1, sizeof(char *));
1.15 millert 275: if (g->mem == NULL)
1.22 tom 276: err(1, NULL);
1.15 millert 277: for (i = 0; grp->gr_mem[i] != NULL; i++) {
278: g->mem[i] = strdup(grp->gr_mem[i]);
279: if (g->mem[i] == NULL)
1.22 tom 280: err(1, NULL);
1.15 millert 281: }
282: g->mem[i] = NULL;
283: g->next = grouplist;
284: grouplist = g;
285: }
286:
287: void
288: usage(void)
289: {
290: extern char *__progname;
291:
292: (void)fprintf(stderr, "usage: %s [-g group] [file]\n", __progname);
293: exit(1);
1.30 martijn 294: }
295:
296: static int
297: isu8cont(unsigned char c)
298: {
299: return (c & (0x80 | 0x40)) == 0x80;
1.1 deraadt 300: }
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