1 /* $NetBSD: wall.c,v 1.30 2015/11/21 14:59:51 christos Exp $ */ 2 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 #include <sys/cdefs.h> 33 #ifndef lint 34 __COPYRIGHT("@(#) Copyright (c) 1988, 1990, 1993\ 35 The Regents of the University of California. All rights reserved."); 36 #endif /* not lint */ 37 38 #ifndef lint 39 #if 0 40 static char sccsid[] = "@(#)wall.c 8.2 (Berkeley) 11/16/93"; 41 #endif 42 __RCSID("$NetBSD: wall.c,v 1.30 2015/11/21 14:59:51 christos Exp $"); 43 #endif /* not lint */ 44 45 /* 46 * This program is not related to David Wall, whose Stanford Ph.D. thesis 47 * is entitled "Mechanisms for Broadcast and Selective Broadcast". 48 */ 49 50 #include <sys/param.h> 51 #include <sys/stat.h> 52 #include <sys/time.h> 53 #include <sys/uio.h> 54 55 #include <ctype.h> 56 #include <err.h> 57 #include <grp.h> 58 #include <errno.h> 59 #include <paths.h> 60 #include <pwd.h> 61 #include <stdio.h> 62 #include <stdlib.h> 63 #include <string.h> 64 #include <unistd.h> 65 #include <util.h> 66 67 #include "utmpentry.h" 68 #include "term_chk.h" 69 70 static void addgroup(char *); 71 static void makemsg(struct iovec *, const char *, int); 72 __dead static void usage(void); 73 74 static struct wallgroup { 75 gid_t gid; 76 char *name; 77 char **mem; 78 struct wallgroup *next; 79 } *grouplist; 80 81 int 82 main(int argc, char **argv) 83 { 84 int ch; 85 struct iovec iov; 86 char *p, **mem; 87 struct utmpentry *ep; 88 gid_t egid; 89 struct wallgroup *wg; 90 struct passwd *pw; 91 int nobanner; 92 93 setprogname(argv[0]); 94 egid = getegid(); 95 if (setegid(getgid()) == -1) 96 err(EXIT_FAILURE, "setegid"); 97 pw = getpwnam("nobody"); 98 if (pw == NULL) 99 errx(EXIT_FAILURE, "Can't find passwd entry for `nobody'"); 100 101 (void)check_sender(NULL, getuid(), egid); 102 103 nobanner = 0; 104 while ((ch = getopt(argc, argv, "g:n")) != -1) 105 switch (ch) { 106 case 'n': 107 /* undoc option for shutdown: suppress banner */ 108 if (geteuid() == 0 || (pw && getuid() == pw->pw_uid)) 109 nobanner = 1; 110 break; 111 case 'g': 112 addgroup(optarg); 113 break; 114 case '?': 115 default: 116 usage(); 117 } 118 argc -= optind; 119 argv += optind; 120 if (argc > 1) 121 usage(); 122 123 makemsg(&iov, *argv, nobanner); 124 125 (void)getutentries(NULL, &ep); 126 (void)setegid(egid); 127 for (; ep; ep = ep->next) { 128 if (grouplist) { 129 int ingroup; 130 131 ingroup = 0; 132 pw = getpwnam(ep->name); 133 if (!pw) 134 continue; 135 for (wg = grouplist; wg && !ingroup; wg = wg->next) { 136 if (wg->gid == pw->pw_gid) 137 ingroup = 1; 138 for (mem = wg->mem; *mem && !ingroup; mem++) 139 if (strcmp(ep->name, *mem) == 0) 140 ingroup = 1; 141 } 142 if (ingroup == 0) 143 continue; 144 } 145 146 /* skip [xgk]dm/xserver entries (":0", ":1", etc.) */ 147 if (ep->line[0] == ':' && isdigit((unsigned char)ep->line[1])) 148 continue; 149 150 if ((p = ttymsg(&iov, 1, ep->line, 60*5)) != NULL) 151 warnx("%s", p); 152 } 153 return EXIT_SUCCESS; 154 } 155 156 static void 157 addgroup(char *name) 158 { 159 size_t i; 160 struct group *grp; 161 struct wallgroup *g; 162 163 grp = getgrnam(name); 164 if ((grp = getgrnam(name)) == NULL) 165 errx(EXIT_FAILURE, "unknown group `%s'", name); 166 for (i = 0; grp->gr_mem[i]; i++) 167 continue; 168 169 g = malloc(sizeof(*g)); 170 if (g == NULL) 171 err(EXIT_FAILURE, "malloc"); 172 g->gid = grp->gr_gid; 173 g->name = name; 174 g->mem = calloc(i + 1, sizeof(*g->mem)); 175 if (g->mem == NULL) 176 err(EXIT_FAILURE, "calloc"); 177 for (i = 0; grp->gr_mem[i] != NULL; i++) { 178 g->mem[i] = strdup(grp->gr_mem[i]); 179 if (g->mem[i] == NULL) 180 err(EXIT_FAILURE, "strdup"); 181 } 182 g->mem[i] = NULL; 183 g->next = grouplist; 184 grouplist = g; 185 } 186 187 static void 188 makebanner(FILE *fp) 189 { 190 const char *whom, *tty; 191 char hostname[MAXHOSTNAMELEN + 1], lbuf[100]; 192 time_t now; 193 struct tm *lt; 194 struct passwd *pw; 195 196 if (!(whom = getlogin())) 197 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???"; 198 (void)gethostname(hostname, sizeof(hostname)); 199 hostname[sizeof(hostname) - 1] = '\0'; 200 (void)time(&now); 201 lt = localtime(&now); 202 203 /* 204 * all this stuff is to blank out a square for the message; 205 * we wrap message lines at column 79, not 80, because some 206 * terminals wrap after 79, some do not, and we can't tell. 207 * Which means that we may leave a non-blank character 208 * in column 80, but that can't be helped. 209 */ 210 (void)fprintf(fp, "\r%79s\r\n", " "); 211 (void)snprintf(lbuf, sizeof lbuf, 212 "Broadcast Message from %s@%s", whom, hostname); 213 (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf); 214 tty = ttyname(STDERR_FILENO); 215 if (tty == NULL) 216 tty = "??"; 217 (void)snprintf(lbuf, sizeof lbuf, " (%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 } 221 222 static void 223 makemsg(struct iovec *iov, const char *fname, int nobanner) 224 { 225 int ch, cnt; 226 struct stat sbuf; 227 FILE *fp; 228 int fd; 229 char *p, tmpname[MAXPATHLEN], lbuf[100]; 230 size_t mbufsize; 231 char *mbuf; 232 233 (void)snprintf(tmpname, sizeof tmpname, "%s/wall.XXXXXX", _PATH_TMP); 234 if ((fd = mkstemp(tmpname)) == -1) 235 err(EXIT_FAILURE, "can't open temporary file"); 236 (void)unlink(tmpname); 237 if (!(fp = fdopen(fd, "r+"))) 238 err(EXIT_FAILURE, "can't open temporary file"); 239 240 if (!nobanner) 241 makebanner(fp); 242 243 (void)fprintf(fp, "%79s\r\n", " "); 244 245 if (fname && !(freopen(fname, "r", stdin))) 246 err(EXIT_FAILURE, "can't read %s", fname); 247 248 while (fgets(lbuf, sizeof(lbuf), stdin)) 249 for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) { 250 if (cnt == 79 || ch == '\n') { 251 for (; cnt < 79; ++cnt) 252 putc(' ', fp); 253 putc('\r', fp); 254 putc('\n', fp); 255 cnt = -1; 256 } 257 if (ch != '\n') 258 putc(ch, fp); 259 } 260 (void)fprintf(fp, "%79s\r\n", " "); 261 rewind(fp); 262 263 if (fstat(fd, &sbuf) == -1) 264 err(EXIT_FAILURE, "can't stat temporary file"); 265 if ((uint64_t)sbuf.st_size > SIZE_T_MAX) 266 errx(EXIT_FAILURE, "file too big"); 267 mbufsize = (size_t)sbuf.st_size; 268 if (!(mbuf = malloc(mbufsize))) 269 err(EXIT_FAILURE, "malloc"); 270 if (fread(mbuf, 1, mbufsize, fp) != mbufsize) 271 err(EXIT_FAILURE, "can't read temporary file"); 272 (void)fclose(fp); 273 iov->iov_base = mbuf; 274 iov->iov_len = mbufsize; 275 } 276 277 static void 278 usage(void) 279 { 280 281 (void)fprintf(stderr, "Usage: %s [-g group] [file]\n", getprogname()); 282 exit(EXIT_FAILURE); 283 } 284
Indexes created Sat Sep 20 22:09:52 GMT 2025