wall.c revision 1.21
1 /* $NetBSD: wall.c,v 1.21 2003/03/27 13:16:19 lukem 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #ifndef lint 38 __COPYRIGHT("@(#) Copyright (c) 1988, 1990, 1993\n\ 39 The Regents of the University of California. All rights reserved.\n"); 40 #endif /* not lint */ 41 42 #ifndef lint 43 #if 0 44 static char sccsid[] = "@(#)wall.c 8.2 (Berkeley) 11/16/93"; 45 #endif 46 __RCSID("$NetBSD: wall.c,v 1.21 2003/03/27 13:16:19 lukem Exp $"); 47 #endif /* not lint */ 48 49 /* 50 * This program is not related to David Wall, whose Stanford Ph.D. thesis 51 * is entitled "Mechanisms for Broadcast and Selective Broadcast". 52 */ 53 54 #include <sys/param.h> 55 #include <sys/stat.h> 56 #include <sys/time.h> 57 #include <sys/uio.h> 58 59 #include <err.h> 60 #include <grp.h> 61 #include <errno.h> 62 #include <paths.h> 63 #include <pwd.h> 64 #include <stdio.h> 65 #include <stdlib.h> 66 #include <string.h> 67 #include <unistd.h> 68 #include <util.h> 69 70 #include "utmpentry.h" 71 72 void addgroup(char *); 73 void makemsg(const char *); 74 int main(int, char **); 75 void usage(void); 76 77 struct wallgroup { 78 gid_t gid; 79 char *name; 80 char **mem; 81 struct wallgroup *next; 82 } *grouplist; 83 84 int nobanner; 85 size_t mbufsize; 86 char *mbuf; 87 88 /* ARGSUSED */ 89 int 90 main(int argc, char **argv) 91 { 92 int ch; 93 struct iovec iov; 94 char *p, **mem; 95 struct utmpentry *ep; 96 gid_t egid; 97 struct wallgroup *wg; 98 struct passwd *pw; 99 100 setprogname(argv[0]); 101 egid = getegid(); 102 if (setegid(getgid()) == -1) 103 err(1, "setegid"); 104 pw = getpwnam("nobody"); 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 if ((p = ttymsg(&iov, 1, ep->line, 60*5)) != NULL) 150 warnx("%s", p); 151 } 152 exit(0); 153 } 154 155 void 156 addgroup(char *name) 157 { 158 int i; 159 struct group *grp; 160 struct wallgroup *g; 161 162 grp = getgrnam(optarg); 163 if ((grp = getgrnam(optarg)) == NULL) 164 errx(1, "unknown group `%s'", optarg); 165 for (i = 0; grp->gr_mem[i]; i++) 166 continue; 167 168 g = (struct wallgroup *)malloc(sizeof *g); 169 if (g == NULL) 170 err(1, "malloc"); 171 g->gid = grp->gr_gid; 172 g->name = name; 173 g->mem = (char **)malloc(i + 1); 174 if (g->mem == NULL) 175 err(1, "malloc"); 176 for (i = 0; grp->gr_mem[i] != NULL; i++) { 177 g->mem[i] = strdup(grp->gr_mem[i]); 178 if (g->mem[i] == NULL) 179 err(1, "malloc"); 180 } 181 g->mem[i] = NULL; 182 g->next = grouplist; 183 grouplist = g; 184 } 185 186 void 187 makemsg(const char *fname) 188 { 189 int ch, cnt; 190 struct tm *lt; 191 struct passwd *pw; 192 struct stat sbuf; 193 time_t now; 194 FILE *fp; 195 int fd; 196 const char *whom; 197 char *p, *tty, tmpname[MAXPATHLEN], lbuf[100], 198 hostname[MAXHOSTNAMELEN+1]; 199 200 (void)snprintf(tmpname, sizeof tmpname, "%s/wall.XXXXXX", _PATH_TMP); 201 if ((fd = mkstemp(tmpname)) == -1) 202 err(1, "can't open temporary file"); 203 (void)unlink(tmpname); 204 if (!(fp = fdopen(fd, "r+"))) 205 err(1, "can't open temporary file"); 206 207 if (!nobanner) { 208 if (!(whom = getlogin())) 209 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???"; 210 (void)gethostname(hostname, sizeof(hostname)); 211 hostname[sizeof(hostname) - 1] = '\0'; 212 (void)time(&now); 213 lt = localtime(&now); 214 215 /* 216 * all this stuff is to blank out a square for the message; 217 * we wrap message lines at column 79, not 80, because some 218 * terminals wrap after 79, some do not, and we can't tell. 219 * Which means that we may leave a non-blank character 220 * in column 80, but that can't be helped. 221 */ 222 (void)fprintf(fp, "\r%79s\r\n", " "); 223 (void)snprintf(lbuf, sizeof lbuf, 224 "Broadcast Message from %s@%s", whom, hostname); 225 (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf); 226 tty = ttyname(STDERR_FILENO); 227 if (tty == NULL) 228 tty = "??"; 229 (void)snprintf(lbuf, sizeof lbuf, 230 " (%s) at %d:%02d %s...", tty, 231 lt->tm_hour, lt->tm_min, lt->tm_zone); 232 (void)fprintf(fp, "%-79.79s\r\n", lbuf); 233 } 234 (void)fprintf(fp, "%79s\r\n", " "); 235 236 if (fname && !(freopen(fname, "r", stdin))) 237 err(1, "can't read %s", fname); 238 while (fgets(lbuf, sizeof(lbuf), stdin)) 239 for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) { 240 if (cnt == 79 || ch == '\n') { 241 for (; cnt < 79; ++cnt) 242 putc(' ', fp); 243 putc('\r', fp); 244 putc('\n', fp); 245 cnt = -1; 246 } 247 if (ch != '\n') 248 putc(ch, fp); 249 } 250 (void)fprintf(fp, "%79s\r\n", " "); 251 rewind(fp); 252 253 if (fstat(fd, &sbuf)) 254 err(1, "can't stat temporary file"); 255 if (sbuf.st_size > SIZE_T_MAX) 256 errx(1, "file too big"); 257 mbufsize = sbuf.st_size; 258 if (!(mbuf = malloc(mbufsize))) 259 err(1, "malloc"); 260 if (fread(mbuf, 1, mbufsize, fp) != mbufsize) 261 err(1, "can't read temporary file"); 262 (void)fclose(fp); 263 } 264 265 void 266 usage(void) 267 { 268 269 (void)fprintf(stderr, "usage: %s [-g group] [file]\n", getprogname()); 270 exit(1); 271 } 272
Indexes created Wed Sep 24 14:09:57 GMT 2025