Annotation of src/usr.bin/wall/wall.c, Revision 1.33
1.33 ! deraadt 1: /* $OpenBSD: wall.c,v 1.32 2016/08/01 20:30:25 martijn 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:
1.33 ! deraadt 118: if (unveil(_PATH_UTMP, "r") == -1)
! 119: err(1, "unveil");
! 120: if (unveil(_PATH_DEV, "w") == -1)
! 121: err(1, "unveil");
1.29 benno 122: if (pledge("stdio rpath wpath getpw proc", NULL) == -1)
123: err(1, "pledge");
124:
1.9 form 125: if (!(fp = fopen(_PATH_UTMP, "r")))
1.21 henning 126: err(1, "cannot read %s", _PATH_UTMP);
1.1 deraadt 127: iov.iov_base = mbuf;
128: iov.iov_len = mbufsize;
1.29 benno 129:
1.15 millert 130: while (fread(&utmp, sizeof(utmp), 1, fp) == 1) {
1.16 deraadt 131: if (!utmp.ut_name[0])
1.1 deraadt 132: continue;
1.6 deraadt 133: if (grouplist) {
1.15 millert 134: ingroup = 0;
135: strncpy(username, utmp.ut_name, sizeof(utmp.ut_name));
136: username[sizeof(utmp.ut_name)] = '\0';
1.6 deraadt 137: pw = getpwnam(username);
138: if (!pw)
139: continue;
140: for (g = grouplist; g && ingroup == 0; g = g->next) {
141: if (g->gid == pw->pw_gid)
142: ingroup = 1;
1.15 millert 143: for (mem = g->mem; *mem && ingroup == 0; mem++)
144: if (strcmp(username, *mem) == 0)
1.6 deraadt 145: ingroup = 1;
146: }
147: if (ingroup == 0)
148: continue;
149: }
1.1 deraadt 150: strncpy(line, utmp.ut_line, sizeof(utmp.ut_line));
151: line[sizeof(utmp.ut_line)] = '\0';
1.29 benno 152: un = malloc(sizeof(struct utmptty));
153: if (un == NULL)
154: err(1, "malloc");
155: un->tty = strndup(line, sizeof(utmp.ut_line));
156: if (un->tty == NULL)
157: err(1, "strndup");
158: SLIST_INSERT_HEAD(&utmphead, un, next);
159: }
160: fclose(fp);
161:
162: if (pledge("stdio rpath wpath proc", NULL) == -1)
163: err(1, "pledge");
164:
165: SLIST_FOREACH(un, &utmphead, next) {
166: if ((p = ttymsg(&iov, 1, un->tty, 60*5)) != NULL)
1.13 deraadt 167: warnx("%s", p);
1.1 deraadt 168: }
1.29 benno 169:
1.1 deraadt 170: exit(0);
171: }
172:
173: void
1.15 millert 174: makemsg(char *fname)
1.1 deraadt 175: {
1.30 martijn 176: int cnt;
1.1 deraadt 177: struct tm *lt;
178: struct passwd *pw;
179: struct stat sbuf;
1.19 deraadt 180: time_t now;
1.1 deraadt 181: FILE *fp;
182: int fd;
1.26 deraadt 183: char *p, *whom, hostname[HOST_NAME_MAX+1], lbuf[100], tmpname[PATH_MAX];
1.11 d 184: char *ttynam;
1.30 martijn 185: unsigned char ch;
1.1 deraadt 186:
1.20 avsm 187: snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXXXXXX", _PATH_TMP);
1.15 millert 188: if ((fd = mkstemp(tmpname)) >= 0) {
189: (void)unlink(tmpname);
190: fp = fdopen(fd, "r+");
191: }
192: if (fd == -1 || fp == NULL)
1.21 henning 193: err(1, "can't open temporary file");
1.1 deraadt 194:
195: if (!nobanner) {
196: if (!(whom = getlogin()))
197: whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
198: (void)gethostname(hostname, sizeof(hostname));
199: (void)time(&now);
200: lt = localtime(&now);
1.11 d 201: if ((ttynam = ttyname(STDERR_FILENO)) == NULL)
202: ttynam = "(not a tty)";
1.1 deraadt 203:
204: /*
205: * all this stuff is to blank out a square for the message;
206: * we wrap message lines at column 79, not 80, because some
207: * terminals wrap after 79, some do not, and we can't tell.
208: * Which means that we may leave a non-blank character
209: * in column 80, but that can't be helped.
210: */
211: (void)fprintf(fp, "\r%79s\r\n", " ");
1.3 deraadt 212: (void)snprintf(lbuf, sizeof lbuf,
213: "Broadcast Message from %s@%s", whom, hostname);
1.1 deraadt 214: (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf);
1.3 deraadt 215: (void)snprintf(lbuf, sizeof lbuf,
1.11 d 216: " (%s) at %d:%02d ...", ttynam,
1.1 deraadt 217: lt->tm_hour, lt->tm_min);
218: (void)fprintf(fp, "%-79.79s\r\n", lbuf);
219: }
220: (void)fprintf(fp, "%79s\r\n", " ");
221:
1.13 deraadt 222: if (fname) {
223: gid_t egid = getegid();
224:
225: setegid(getgid());
226: if (freopen(fname, "r", stdin) == NULL)
1.21 henning 227: err(1, "can't read %s", fname);
1.13 deraadt 228: setegid(egid);
229: }
1.1 deraadt 230: while (fgets(lbuf, sizeof(lbuf), stdin))
231: for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) {
1.30 martijn 232: if (cnt == 79 || ch == '\n') {
233: for (; cnt < 79; ++cnt)
1.1 deraadt 234: putc(' ', fp);
235: putc('\r', fp);
236: putc('\n', fp);
237: cnt = -1;
1.30 martijn 238: } else if (!isu8cont(ch))
1.32 martijn 239: putc(isprint(ch) || isspace(ch) || ch == '\a' ?
1.30 martijn 240: ch : '?', fp);
1.1 deraadt 241: }
242: (void)fprintf(fp, "%79s\r\n", " ");
243: rewind(fp);
244:
1.9 form 245: if (fstat(fd, &sbuf))
1.21 henning 246: err(1, "can't stat temporary file");
1.1 deraadt 247: mbufsize = sbuf.st_size;
1.22 tom 248: mbuf = malloc((u_int)mbufsize);
249: if (mbuf == NULL)
250: err(1, NULL);
1.9 form 251: if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
1.21 henning 252: err(1, "can't read temporary file");
1.1 deraadt 253: (void)close(fd);
1.15 millert 254: }
255:
256: void
257: addgroup(struct group *grp, char *name)
258: {
259: int i;
260: struct wallgroup *g;
261:
262: for (i = 0; grp->gr_mem[i]; i++)
263: ;
264:
1.27 deraadt 265: g = malloc(sizeof *g);
1.15 millert 266: if (g == NULL)
1.22 tom 267: err(1, NULL);
1.15 millert 268: g->gid = grp->gr_gid;
269: g->name = name;
1.27 deraadt 270: g->mem = calloc(i + 1, sizeof(char *));
1.15 millert 271: if (g->mem == NULL)
1.22 tom 272: err(1, NULL);
1.15 millert 273: for (i = 0; grp->gr_mem[i] != NULL; i++) {
274: g->mem[i] = strdup(grp->gr_mem[i]);
275: if (g->mem[i] == NULL)
1.22 tom 276: err(1, NULL);
1.15 millert 277: }
278: g->mem[i] = NULL;
279: g->next = grouplist;
280: grouplist = g;
281: }
282:
283: void
284: usage(void)
285: {
286: extern char *__progname;
287:
288: (void)fprintf(stderr, "usage: %s [-g group] [file]\n", __progname);
289: exit(1);
1.30 martijn 290: }
291:
292: static int
293: isu8cont(unsigned char c)
294: {
295: return (c & (0x80 | 0x40)) == 0x80;
1.1 deraadt 296: }
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