Annotation of src/usr.bin/wall/wall.c, Revision 1.32
1.32 ! martijn 1: /* $OpenBSD: wall.c,v 1.31 2016/05/08 17:09:42 schwarze 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: /* ARGSUSED */
78: int
1.15 millert 79: main(int argc, char **argv)
1.1 deraadt 80: {
1.15 millert 81: FILE *fp;
82: int ch, ingroup;
1.1 deraadt 83: struct iovec iov;
84: struct utmp utmp;
1.15 millert 85: char *p, **mem;
1.1 deraadt 86: char line[sizeof(utmp.ut_line) + 1];
1.15 millert 87: char username[sizeof(utmp.ut_name) + 1];
88: struct passwd *pw;
89: struct group *grp;
1.6 deraadt 90: struct wallgroup *g;
1.29 benno 91: struct utmptty *un;
92: SLIST_HEAD(,utmptty) utmphead;
93: SLIST_INIT(&utmphead);
1.1 deraadt 94:
1.8 millert 95: while ((ch = getopt(argc, argv, "ng:")) != -1)
1.1 deraadt 96: switch (ch) {
97: case 'n':
98: /* undoc option for shutdown: suppress banner */
1.15 millert 99: pw = getpwnam("nobody");
100: if (geteuid() == 0 || (pw && getuid() == pw->pw_uid))
1.1 deraadt 101: nobanner = 1;
102: break;
1.6 deraadt 103: case 'g':
1.15 millert 104: if ((grp = getgrnam(optarg)) == NULL)
105: errx(1, "unknown group `%s'", optarg);
106: addgroup(grp, optarg);
1.6 deraadt 107: break;
1.1 deraadt 108: default:
1.15 millert 109: usage();
1.1 deraadt 110: }
111: argc -= optind;
112: argv += optind;
113: if (argc > 1)
1.15 millert 114: usage();
1.6 deraadt 115:
1.1 deraadt 116: makemsg(*argv);
117:
1.29 benno 118: if (pledge("stdio rpath wpath getpw proc", NULL) == -1)
119: err(1, "pledge");
120:
1.9 form 121: if (!(fp = fopen(_PATH_UTMP, "r")))
1.21 henning 122: err(1, "cannot read %s", _PATH_UTMP);
1.1 deraadt 123: iov.iov_base = mbuf;
124: iov.iov_len = mbufsize;
1.29 benno 125:
1.15 millert 126: while (fread(&utmp, sizeof(utmp), 1, fp) == 1) {
1.16 deraadt 127: if (!utmp.ut_name[0])
1.1 deraadt 128: continue;
1.6 deraadt 129: if (grouplist) {
1.15 millert 130: ingroup = 0;
131: strncpy(username, utmp.ut_name, sizeof(utmp.ut_name));
132: username[sizeof(utmp.ut_name)] = '\0';
1.6 deraadt 133: pw = getpwnam(username);
134: if (!pw)
135: continue;
136: for (g = grouplist; g && ingroup == 0; g = g->next) {
137: if (g->gid == pw->pw_gid)
138: ingroup = 1;
1.15 millert 139: for (mem = g->mem; *mem && ingroup == 0; mem++)
140: if (strcmp(username, *mem) == 0)
1.6 deraadt 141: ingroup = 1;
142: }
143: if (ingroup == 0)
144: continue;
145: }
1.1 deraadt 146: strncpy(line, utmp.ut_line, sizeof(utmp.ut_line));
147: line[sizeof(utmp.ut_line)] = '\0';
1.29 benno 148: un = malloc(sizeof(struct utmptty));
149: if (un == NULL)
150: err(1, "malloc");
151: un->tty = strndup(line, sizeof(utmp.ut_line));
152: if (un->tty == NULL)
153: err(1, "strndup");
154: SLIST_INSERT_HEAD(&utmphead, un, next);
155: }
156: fclose(fp);
157:
158: if (pledge("stdio rpath wpath proc", NULL) == -1)
159: err(1, "pledge");
160:
161: SLIST_FOREACH(un, &utmphead, next) {
162: if ((p = ttymsg(&iov, 1, un->tty, 60*5)) != NULL)
1.13 deraadt 163: warnx("%s", p);
1.1 deraadt 164: }
1.29 benno 165:
1.1 deraadt 166: exit(0);
167: }
168:
169: void
1.15 millert 170: makemsg(char *fname)
1.1 deraadt 171: {
1.30 martijn 172: int cnt;
1.1 deraadt 173: struct tm *lt;
174: struct passwd *pw;
175: struct stat sbuf;
1.19 deraadt 176: time_t now;
1.1 deraadt 177: FILE *fp;
178: int fd;
1.26 deraadt 179: char *p, *whom, hostname[HOST_NAME_MAX+1], lbuf[100], tmpname[PATH_MAX];
1.11 d 180: char *ttynam;
1.30 martijn 181: unsigned char ch;
1.1 deraadt 182:
1.20 avsm 183: snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXXXXXX", _PATH_TMP);
1.15 millert 184: if ((fd = mkstemp(tmpname)) >= 0) {
185: (void)unlink(tmpname);
186: fp = fdopen(fd, "r+");
187: }
188: if (fd == -1 || fp == NULL)
1.21 henning 189: err(1, "can't open temporary file");
1.1 deraadt 190:
191: if (!nobanner) {
192: if (!(whom = getlogin()))
193: whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
194: (void)gethostname(hostname, sizeof(hostname));
195: (void)time(&now);
196: lt = localtime(&now);
1.11 d 197: if ((ttynam = ttyname(STDERR_FILENO)) == NULL)
198: ttynam = "(not a tty)";
1.1 deraadt 199:
200: /*
201: * all this stuff is to blank out a square for the message;
202: * we wrap message lines at column 79, not 80, because some
203: * terminals wrap after 79, some do not, and we can't tell.
204: * Which means that we may leave a non-blank character
205: * in column 80, but that can't be helped.
206: */
207: (void)fprintf(fp, "\r%79s\r\n", " ");
1.3 deraadt 208: (void)snprintf(lbuf, sizeof lbuf,
209: "Broadcast Message from %s@%s", whom, hostname);
1.1 deraadt 210: (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf);
1.3 deraadt 211: (void)snprintf(lbuf, sizeof lbuf,
1.11 d 212: " (%s) at %d:%02d ...", ttynam,
1.1 deraadt 213: lt->tm_hour, lt->tm_min);
214: (void)fprintf(fp, "%-79.79s\r\n", lbuf);
215: }
216: (void)fprintf(fp, "%79s\r\n", " ");
217:
1.13 deraadt 218: if (fname) {
219: gid_t egid = getegid();
220:
221: setegid(getgid());
222: if (freopen(fname, "r", stdin) == NULL)
1.21 henning 223: err(1, "can't read %s", fname);
1.13 deraadt 224: setegid(egid);
225: }
1.1 deraadt 226: while (fgets(lbuf, sizeof(lbuf), stdin))
227: for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) {
1.30 martijn 228: if (cnt == 79 || ch == '\n') {
229: for (; cnt < 79; ++cnt)
1.1 deraadt 230: putc(' ', fp);
231: putc('\r', fp);
232: putc('\n', fp);
233: cnt = -1;
1.30 martijn 234: } else if (!isu8cont(ch))
1.32 ! martijn 235: putc(isprint(ch) || isspace(ch) || ch == '\a' ?
1.30 martijn 236: ch : '?', fp);
1.1 deraadt 237: }
238: (void)fprintf(fp, "%79s\r\n", " ");
239: rewind(fp);
240:
1.9 form 241: if (fstat(fd, &sbuf))
1.21 henning 242: err(1, "can't stat temporary file");
1.1 deraadt 243: mbufsize = sbuf.st_size;
1.22 tom 244: mbuf = malloc((u_int)mbufsize);
245: if (mbuf == NULL)
246: err(1, NULL);
1.9 form 247: if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
1.21 henning 248: err(1, "can't read temporary file");
1.1 deraadt 249: (void)close(fd);
1.15 millert 250: }
251:
252: void
253: addgroup(struct group *grp, char *name)
254: {
255: int i;
256: struct wallgroup *g;
257:
258: for (i = 0; grp->gr_mem[i]; i++)
259: ;
260:
1.27 deraadt 261: g = malloc(sizeof *g);
1.15 millert 262: if (g == NULL)
1.22 tom 263: err(1, NULL);
1.15 millert 264: g->gid = grp->gr_gid;
265: g->name = name;
1.27 deraadt 266: g->mem = calloc(i + 1, sizeof(char *));
1.15 millert 267: if (g->mem == NULL)
1.22 tom 268: err(1, NULL);
1.15 millert 269: for (i = 0; grp->gr_mem[i] != NULL; i++) {
270: g->mem[i] = strdup(grp->gr_mem[i]);
271: if (g->mem[i] == NULL)
1.22 tom 272: err(1, NULL);
1.15 millert 273: }
274: g->mem[i] = NULL;
275: g->next = grouplist;
276: grouplist = g;
277: }
278:
279: void
280: usage(void)
281: {
282: extern char *__progname;
283:
284: (void)fprintf(stderr, "usage: %s [-g group] [file]\n", __progname);
285: exit(1);
1.30 martijn 286: }
287:
288: static int
289: isu8cont(unsigned char c)
290: {
291: return (c & (0x80 | 0x40)) == 0x80;
1.1 deraadt 292: }