wall.c revision 1.23
1 /* $NetBSD: wall.c,v 1.23 2003/04/21 00:05:30 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. 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 1.23 2003/04/21 00:05:30 christos 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 #include "term_chk.h" 72 73 void addgroup(char *); 74 void makemsg(const char *); 75 int main(int, char **); 76 void usage(void); 77 78 struct wallgroup { 79 gid_t gid; 80 char *name; 81 char **mem; 82 struct wallgroup *next; 83 } *grouplist; 84 85 int nobanner; 86 size_t mbufsize; 87 char *mbuf; 88 89 /* ARGSUSED */ 90 int 91 main(int argc, char **argv) 92 { 93 int ch; 94 struct iovec iov; 95 char *p, **mem; 96 struct utmpentry *ep; 97 gid_t egid; 98 struct wallgroup *wg; 99 struct passwd *pw; 100 time_t atime; 101 102 setprogname(argv[0]); 103 egid = getegid(); 104 if (setegid(getgid()) == -1) 105 err(1, "setegid"); 106 pw = getpwnam("nobody"); 107 108 (void)check_sender(&atime, getuid(), egid); 109 110 while ((ch = getopt(argc, argv, "g:n")) != -1) 111 switch (ch) { 112 case 'n': 113 /* undoc option for shutdown: suppress banner */ 114 if (geteuid() == 0 || (pw && getuid() == pw->pw_uid)) 115 nobanner = 1; 116 break; 117 case 'g': 118 addgroup(optarg); 119 break; 120 case '?': 121 default: 122 usage(); 123 } 124 argc -= optind; 125 argv += optind; 126 if (argc > 1) 127 usage(); 128 129 makemsg(*argv); 130 131 iov.iov_base = mbuf; 132 iov.iov_len = mbufsize; 133 (void)getutentries(NULL, &ep); 134 (void)setegid(egid); 135 for (; ep; ep = ep->next) { 136 if (grouplist) { 137 int ingroup; 138 139 ingroup = 0; 140 pw = getpwnam(ep->name); 141 if (!pw) 142 continue; 143 for (wg = grouplist; wg && !ingroup; wg = wg->next) { 144 if (wg->gid == pw->pw_gid) 145 ingroup = 1; 146 for (mem = wg->mem; *mem && !ingroup; mem++) 147 if (strcmp(ep->name, *mem) == 0) 148 ingroup = 1; 149 } 150 if (ingroup == 0) 151 continue; 152 } 153 if ((p = ttymsg(&iov, 1, ep->line, 60*5)) != NULL) 154 warnx("%s", p); 155 } 156 exit(0); 157 } 158 159 void 160 addgroup(char *name) 161 { 162 int i; 163 struct group *grp; 164 struct wallgroup *g; 165 166 grp = getgrnam(name); 167 if ((grp = getgrnam(name)) == NULL) 168 errx(1, "unknown group `%s'", name); 169 for (i = 0; grp->gr_mem[i]; i++) 170 continue; 171 172 g = (struct wallgroup *)malloc(sizeof *g); 173 if (g == NULL) 174 err(1, "malloc"); 175 g->gid = grp->gr_gid; 176 g->name = name; 177 g->mem = (char **)malloc(i + 1); 178 if (g->mem == NULL) 179 err(1, "malloc"); 180 for (i = 0; grp->gr_mem[i] != NULL; i++) { 181 g->mem[i] = strdup(grp->gr_mem[i]); 182 if (g->mem[i] == NULL) 183 err(1, "malloc"); 184 } 185 g->mem[i] = NULL; 186 g->next = grouplist; 187 grouplist = g; 188 } 189 190 void 191 makemsg(const char *fname) 192 { 193 int ch, cnt; 194 struct tm *lt; 195 struct passwd *pw; 196 struct stat sbuf; 197 time_t now; 198 FILE *fp; 199 int fd; 200 const char *whom; 201 char *p, *tty, tmpname[MAXPATHLEN], lbuf[100], 202 hostname[MAXHOSTNAMELEN+1]; 203 204 (void)snprintf(tmpname, sizeof tmpname, "%s/wall.XXXXXX", _PATH_TMP); 205 if ((fd = mkstemp(tmpname)) == -1) 206 err(1, "can't open temporary file"); 207 (void)unlink(tmpname); 208 if (!(fp = fdopen(fd, "r+"))) 209 err(1, "can't open temporary file"); 210 211 if (!nobanner) { 212 if (!(whom = getlogin())) 213 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???"; 214 (void)gethostname(hostname, sizeof(hostname)); 215 hostname[sizeof(hostname) - 1] = '\0'; 216 (void)time(&now); 217 lt = localtime(&now); 218 219 /* 220 * all this stuff is to blank out a square for the message; 221 * we wrap message lines at column 79, not 80, because some 222 * terminals wrap after 79, some do not, and we can't tell. 223 * Which means that we may leave a non-blank character 224 * in column 80, but that can't be helped. 225 */ 226 (void)fprintf(fp, "\r%79s\r\n", " "); 227 (void)snprintf(lbuf, sizeof lbuf, 228 "Broadcast Message from %s@%s", whom, hostname); 229 (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf); 230 tty = ttyname(STDERR_FILENO); 231 if (tty == NULL) 232 tty = "??"; 233 (void)snprintf(lbuf, sizeof lbuf, 234 " (%s) at %d:%02d %s...", tty, 235 lt->tm_hour, lt->tm_min, lt->tm_zone); 236 (void)fprintf(fp, "%-79.79s\r\n", lbuf); 237 } 238 (void)fprintf(fp, "%79s\r\n", " "); 239 240 if (fname && !(freopen(fname, "r", stdin))) 241 err(1, "can't read %s", fname); 242 while (fgets(lbuf, sizeof(lbuf), stdin)) 243 for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) { 244 if (cnt == 79 || ch == '\n') { 245 for (; cnt < 79; ++cnt) 246 putc(' ', fp); 247 putc('\r', fp); 248 putc('\n', fp); 249 cnt = -1; 250 } 251 if (ch != '\n') 252 putc(ch, fp); 253 } 254 (void)fprintf(fp, "%79s\r\n", " "); 255 rewind(fp); 256 257 if (fstat(fd, &sbuf)) 258 err(1, "can't stat temporary file"); 259 if (sbuf.st_size > SIZE_T_MAX) 260 errx(1, "file too big"); 261 mbufsize = sbuf.st_size; 262 if (!(mbuf = malloc(mbufsize))) 263 err(1, "malloc"); 264 if (fread(mbuf, 1, mbufsize, fp) != mbufsize) 265 err(1, "can't read temporary file"); 266 (void)fclose(fp); 267 } 268 269 void 270 usage(void) 271 { 272 273 (void)fprintf(stderr, "usage: %s [-g group] [file]\n", getprogname()); 274 exit(1); 275 } 276
Indexes created Fri Sep 26 08:10:20 GMT 2025