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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#) Copyright (c) 1988, 1990, 1993 The Regents of the University of California. All rights reserved. 34 * @(#)wall.c 8.2 (Berkeley) 11/16/93 35 * $FreeBSD: src/usr.bin/wall/wall.c,v 1.13.2.6 2001/10/18 08:08:17 des Exp $ 36 * $DragonFly: src/usr.bin/wall/wall.c,v 1.4 2005/08/31 16:27:53 liamfoy Exp $ 37 */ 38 39 /* 40 * This program is not related to David Wall, whose Stanford Ph.D. thesis 41 * is entitled "Mechanisms for Broadcast and Selective Broadcast". 42 */ 43 44 #include <sys/param.h> 45 #include <sys/stat.h> 46 #include <sys/uio.h> 47 48 #include <ctype.h> 49 #include <err.h> 50 #include <grp.h> 51 #include <locale.h> 52 #include <paths.h> 53 #include <pwd.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <time.h> 58 #include <unistd.h> 59 #include <utmp.h> 60 61 #include "ttymsg.h" 62 63 static void makemsg(char *); 64 static void usage(void); 65 66 struct wallgroup { 67 struct wallgroup *next; 68 char *name; 69 gid_t gid; 70 } *grouplist; 71 int nobanner; 72 int mbufsize; 73 char *mbuf; 74 75 int 76 main(int argc, char *argv[]) 77 { 78 struct iovec iov; 79 struct utmp utmp; 80 int ch; 81 int ingroup; 82 FILE *fp; 83 struct wallgroup *g; 84 struct group *grp; 85 char **np; 86 const char *p; 87 struct passwd *pw; 88 char line[sizeof(utmp.ut_line) + 1]; 89 char username[sizeof(utmp.ut_name) + 1]; 90 91 (void)setlocale(LC_CTYPE, ""); 92 93 while ((ch = getopt(argc, argv, "g:n")) != -1) 94 switch (ch) { 95 case 'n': 96 /* undoc option for shutdown: suppress banner */ 97 if (geteuid() == 0) 98 nobanner = 1; 99 break; 100 case 'g': 101 g = (struct wallgroup *)malloc(sizeof *g); 102 g->next = grouplist; 103 g->name = optarg; 104 g->gid = -1; 105 grouplist = g; 106 break; 107 case '?': 108 default: 109 usage(); 110 } 111 argc -= optind; 112 argv += optind; 113 if (argc > 1) 114 usage(); 115 116 for (g = grouplist; g; g = g->next) { 117 grp = getgrnam(g->name); 118 if (grp != NULL) 119 g->gid = grp->gr_gid; 120 else 121 warnx("%s: no such group", g->name); 122 } 123 124 makemsg(*argv); 125 126 if (!(fp = fopen(_PATH_UTMP, "r"))) 127 err(1, "cannot read %s", _PATH_UTMP); 128 iov.iov_base = mbuf; 129 iov.iov_len = mbufsize; 130 /* NOSTRICT */ 131 while (fread((char *)&utmp, sizeof(utmp), 1, fp) == 1) { 132 if (!utmp.ut_name[0]) 133 continue; 134 if (grouplist) { 135 ingroup = 0; 136 strlcpy(username, utmp.ut_name, sizeof(utmp.ut_name)); 137 pw = getpwnam(username); 138 if (!pw) 139 continue; 140 for (g = grouplist; g && ingroup == 0; g = g->next) { 141 if (g->gid == (gid_t)-1) 142 continue; 143 if (g->gid == pw->pw_gid) 144 ingroup = 1; 145 else if ((grp = getgrgid(g->gid)) != NULL) { 146 for (np = grp->gr_mem; *np; np++) { 147 if (strcmp(*np, username) == 0) { 148 ingroup = 1; 149 break; 150 } 151 } 152 } 153 } 154 if (ingroup == 0) 155 continue; 156 } 157 strncpy(line, utmp.ut_line, sizeof(utmp.ut_line)); 158 line[sizeof(utmp.ut_line)] = '\0'; 159 if ((p = ttymsg(&iov, 1, line, 60*5)) != NULL) 160 warnx("%s", p); 161 } 162 exit(0); 163 } 164 165 static void 166 usage(void) 167 { 168 (void)fprintf(stderr, "usage: wall [-g group] [file]\n"); 169 exit(1); 170 } 171 172 void 173 makemsg(char *fname) 174 { 175 int cnt; 176 unsigned char ch; 177 struct tm *lt; 178 struct passwd *pw; 179 struct stat sbuf; 180 time_t now; 181 FILE *fp; 182 int fd; 183 char *p, hostname[MAXHOSTNAMELEN], lbuf[256], tmpname[MAXPATHLEN]; 184 const char *tty; 185 const char *whom; 186 gid_t egid; 187 188 (void)snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP); 189 if ((fd = mkstemp(tmpname)) == -1 || !(fp = fdopen(fd, "r+"))) 190 err(1, "can't open temporary file"); 191 (void)unlink(tmpname); 192 193 if (!nobanner) { 194 tty = ttyname(STDERR_FILENO); 195 if (tty == NULL) 196 tty = "no tty"; 197 198 if (!(whom = getlogin())) 199 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???"; 200 (void)gethostname(hostname, sizeof(hostname)); 201 (void)time(&now); 202 lt = localtime(&now); 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", " "); 212 (void)snprintf(lbuf, sizeof(lbuf), 213 "Broadcast Message from %s@%s", 214 whom, hostname); 215 (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf); 216 (void)snprintf(lbuf, sizeof(lbuf), 217 " (%s) at %d:%02d %s...", tty, 218 lt->tm_hour, lt->tm_min, lt->tm_zone); 219 (void)fprintf(fp, "%-79.79s\r\n", lbuf); 220 } 221 (void)fprintf(fp, "%79s\r\n", " "); 222 223 if (fname) { 224 egid = getegid(); 225 setegid(getgid()); 226 if (freopen(fname, "r", stdin) == NULL) 227 err(1, "can't read %s", fname); 228 setegid(egid); 229 } 230 while (fgets(lbuf, sizeof(lbuf), stdin)) 231 for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) { 232 if (ch == '\r') { 233 cnt = 0; 234 } else if (cnt == 79 || ch == '\n') { 235 for (; cnt < 79; ++cnt) 236 putc(' ', fp); 237 putc('\r', fp); 238 putc('\n', fp); 239 cnt = 0; 240 } else if (((ch & 0x80) && ch < 0xA0) || 241 /* disable upper controls */ 242 (!isprint(ch) && !isspace(ch) && 243 ch != '\a' && ch != '\b') 244 ) { 245 if (ch & 0x80) { 246 ch &= 0x7F; 247 putc('M', fp); 248 if (++cnt == 79) { 249 putc('\r', fp); 250 putc('\n', fp); 251 cnt = 0; 252 } 253 putc('-', fp); 254 if (++cnt == 79) { 255 putc('\r', fp); 256 putc('\n', fp); 257 cnt = 0; 258 } 259 } 260 if (iscntrl(ch)) { 261 ch ^= 040; 262 putc('^', fp); 263 if (++cnt == 79) { 264 putc('\r', fp); 265 putc('\n', fp); 266 cnt = 0; 267 } 268 } 269 putc(ch, fp); 270 } else { 271 putc(ch, fp); 272 } 273 } 274 (void)fprintf(fp, "%79s\r\n", " "); 275 rewind(fp); 276 277 if (fstat(fd, &sbuf)) 278 err(1, "can't stat temporary file"); 279 mbufsize = sbuf.st_size; 280 if (!(mbuf = malloc((u_int)mbufsize))) 281 err(1, "out of memory"); 282 if ((int)fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize) 283 err(1, "can't read temporary file"); 284 (void)close(fd); 285 } 286