wall.c revision 1.27
1 /* $NetBSD: wall.c,v 1.27 2009/02/15 06:06:55 dholland 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 1.27 2009/02/15 06:06:55 dholland 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 void addgroup(char *); 71 void makemsg(const char *); 72 int main(int, char **); 73 void usage(void); 74 75 struct wallgroup { 76 gid_t gid; 77 char *name; 78 char **mem; 79 struct wallgroup *next; 80 } *grouplist; 81 82 int nobanner; 83 size_t mbufsize; 84 char *mbuf; 85 86 /* ARGSUSED */ 87 int 88 main(int argc, char **argv) 89 { 90 int ch; 91 struct iovec iov; 92 char *p, **mem; 93 struct utmpentry *ep; 94 gid_t egid; 95 struct wallgroup *wg; 96 struct passwd *pw; 97 98 setprogname(argv[0]); 99 egid = getegid(); 100 if (setegid(getgid()) == -1) 101 err(1, "setegid"); 102 pw = getpwnam("nobody"); 103 104 (void)check_sender(NULL, getuid(), egid); 105 106 while ((ch = getopt(argc, argv, "g:n")) != -1) 107 switch (ch) { 108 case 'n': 109 /* undoc option for shutdown: suppress banner */ 110 if (geteuid() == 0 || (pw && getuid() == pw->pw_uid)) 111 nobanner = 1; 112 break; 113 case 'g': 114 addgroup(optarg); 115 break; 116 case '?': 117 default: 118 usage(); 119 } 120 argc -= optind; 121 argv += optind; 122 if (argc > 1) 123 usage(); 124 125 makemsg(*argv); 126 127 iov.iov_base = mbuf; 128 iov.iov_len = mbufsize; 129 (void)getutentries(NULL, &ep); 130 (void)setegid(egid); 131 for (; ep; ep = ep->next) { 132 if (grouplist) { 133 int ingroup; 134 135 ingroup = 0; 136 pw = getpwnam(ep->name); 137 if (!pw) 138 continue; 139 for (wg = grouplist; wg && !ingroup; wg = wg->next) { 140 if (wg->gid == pw->pw_gid) 141 ingroup = 1; 142 for (mem = wg->mem; *mem && !ingroup; mem++) 143 if (strcmp(ep->name, *mem) == 0) 144 ingroup = 1; 145 } 146 if (ingroup == 0) 147 continue; 148 } 149 150 /* skip [xgk]dm/xserver entries (":0", ":1", etc.) */ 151 if (ep->line[0] == ':' && isdigit((unsigned char)ep->line[1])) 152 continue; 153 154 if ((p = ttymsg(&iov, 1, ep->line, 60*5)) != NULL) 155 warnx("%s", p); 156 } 157 exit(0); 158 } 159 160 void 161 addgroup(char *name) 162 { 163 int i; 164 struct group *grp; 165 struct wallgroup *g; 166 167 grp = getgrnam(name); 168 if ((grp = getgrnam(name)) == NULL) 169 errx(1, "unknown group `%s'", name); 170 for (i = 0; grp->gr_mem[i]; i++) 171 continue; 172 173 g = (struct wallgroup *)malloc(sizeof *g); 174 if (g == NULL) 175 err(1, "malloc"); 176 g->gid = grp->gr_gid; 177 g->name = name; 178 g->mem = (char **)malloc(i + 1); 179 if (g->mem == NULL) 180 err(1, "malloc"); 181 for (i = 0; grp->gr_mem[i] != NULL; i++) { 182 g->mem[i] = strdup(grp->gr_mem[i]); 183 if (g->mem[i] == NULL) 184 err(1, "malloc"); 185 } 186 g->mem[i] = NULL; 187 g->next = grouplist; 188 grouplist = g; 189 } 190 191 void 192 makemsg(const char *fname) 193 { 194 int ch, cnt; 195 struct tm *lt; 196 struct passwd *pw; 197 struct stat sbuf; 198 time_t now; 199 FILE *fp; 200 int fd; 201 const char *whom; 202 char *p, *tty, tmpname[MAXPATHLEN], lbuf[100], 203 hostname[MAXHOSTNAMELEN+1]; 204 205 (void)snprintf(tmpname, sizeof tmpname, "%s/wall.XXXXXX", _PATH_TMP); 206 if ((fd = mkstemp(tmpname)) == -1) 207 err(1, "can't open temporary file"); 208 (void)unlink(tmpname); 209 if (!(fp = fdopen(fd, "r+"))) 210 err(1, "can't open temporary file"); 211 212 if (!nobanner) { 213 if (!(whom = getlogin())) 214 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???"; 215 (void)gethostname(hostname, sizeof(hostname)); 216 hostname[sizeof(hostname) - 1] = '\0'; 217 (void)time(&now); 218 lt = localtime(&now); 219 220 /* 221 * all this stuff is to blank out a square for the message; 222 * we wrap message lines at column 79, not 80, because some 223 * terminals wrap after 79, some do not, and we can't tell. 224 * Which means that we may leave a non-blank character 225 * in column 80, but that can't be helped. 226 */ 227 (void)fprintf(fp, "\r%79s\r\n", " "); 228 (void)snprintf(lbuf, sizeof lbuf, 229 "Broadcast Message from %s@%s", whom, hostname); 230 (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf); 231 tty = ttyname(STDERR_FILENO); 232 if (tty == NULL) 233 tty = "??"; 234 (void)snprintf(lbuf, sizeof lbuf, 235 " (%s) at %d:%02d %s...", tty, 236 lt->tm_hour, lt->tm_min, lt->tm_zone); 237 (void)fprintf(fp, "%-79.79s\r\n", lbuf); 238 } 239 (void)fprintf(fp, "%79s\r\n", " "); 240 241 if (fname && !(freopen(fname, "r", stdin))) 242 err(1, "can't read %s", fname); 243 while (fgets(lbuf, sizeof(lbuf), stdin)) 244 for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) { 245 if (cnt == 79 || ch == '\n') { 246 for (; cnt < 79; ++cnt) 247 putc(' ', fp); 248 putc('\r', fp); 249 putc('\n', fp); 250 cnt = -1; 251 } 252 if (ch != '\n') 253 putc(ch, fp); 254 } 255 (void)fprintf(fp, "%79s\r\n", " "); 256 rewind(fp); 257 258 if (fstat(fd, &sbuf)) 259 err(1, "can't stat temporary file"); 260 if (sbuf.st_size > SIZE_T_MAX) 261 errx(1, "file too big"); 262 mbufsize = sbuf.st_size; 263 if (!(mbuf = malloc(mbufsize))) 264 err(1, "malloc"); 265 if (fread(mbuf, 1, mbufsize, fp) != mbufsize) 266 err(1, "can't read temporary file"); 267 (void)fclose(fp); 268 } 269 270 void 271 usage(void) 272 { 273 274 (void)fprintf(stderr, "usage: %s [-g group] [file]\n", getprogname()); 275 exit(1); 276 } 277
Indexes created Sat Sep 27 14:09:57 GMT 2025