wall.c revision 1.25
1 /* $NetBSD: wall.c,v 1.25 2004/10/27 17:49:19 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\n\ 35 The Regents of the University of California. All rights reserved.\n"); 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 1.25 2004/10/27 17:49:19 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 <err.h> 56 #include <grp.h> 57 #include <errno.h> 58 #include <paths.h> 59 #include <pwd.h> 60 #include <stdio.h> 61 #include <stdlib.h> 62 #include <string.h> 63 #include <unistd.h> 64 #include <util.h> 65 66 #include "utmpentry.h" 67 #include "term_chk.h" 68 69 void addgroup(char *); 70 void makemsg(const char *); 71 int main(int, char **); 72 void usage(void); 73 74 struct wallgroup { 75 gid_t gid; 76 char *name; 77 char **mem; 78 struct wallgroup *next; 79 } *grouplist; 80 81 int nobanner; 82 size_t mbufsize; 83 char *mbuf; 84 85 /* ARGSUSED */ 86 int 87 main(int argc, char **argv) 88 { 89 int ch; 90 struct iovec iov; 91 char *p, **mem; 92 struct utmpentry *ep; 93 gid_t egid; 94 struct wallgroup *wg; 95 struct passwd *pw; 96 97 setprogname(argv[0]); 98 egid = getegid(); 99 if (setegid(getgid()) == -1) 100 err(1, "setegid"); 101 pw = getpwnam("nobody"); 102 103 (void)check_sender(NULL, getuid(), egid); 104 105 while ((ch = getopt(argc, argv, "g:n")) != -1) 106 switch (ch) { 107 case 'n': 108 /* undoc option for shutdown: suppress banner */ 109 if (geteuid() == 0 || (pw && getuid() == pw->pw_uid)) 110 nobanner = 1; 111 break; 112 case 'g': 113 addgroup(optarg); 114 break; 115 case '?': 116 default: 117 usage(); 118 } 119 argc -= optind; 120 argv += optind; 121 if (argc > 1) 122 usage(); 123 124 makemsg(*argv); 125 126 iov.iov_base = mbuf; 127 iov.iov_len = mbufsize; 128 (void)getutentries(NULL, &ep); 129 (void)setegid(egid); 130 for (; ep; ep = ep->next) { 131 if (grouplist) { 132 int ingroup; 133 134 ingroup = 0; 135 pw = getpwnam(ep->name); 136 if (!pw) 137 continue; 138 for (wg = grouplist; wg && !ingroup; wg = wg->next) { 139 if (wg->gid == pw->pw_gid) 140 ingroup = 1; 141 for (mem = wg->mem; *mem && !ingroup; mem++) 142 if (strcmp(ep->name, *mem) == 0) 143 ingroup = 1; 144 } 145 if (ingroup == 0) 146 continue; 147 } 148 if ((p = ttymsg(&iov, 1, ep->line, 60*5)) != NULL) 149 warnx("%s", p); 150 } 151 exit(0); 152 } 153 154 void 155 addgroup(char *name) 156 { 157 int i; 158 struct group *grp; 159 struct wallgroup *g; 160 161 grp = getgrnam(name); 162 if ((grp = getgrnam(name)) == NULL) 163 errx(1, "unknown group `%s'", name); 164 for (i = 0; grp->gr_mem[i]; i++) 165 continue; 166 167 g = (struct wallgroup *)malloc(sizeof *g); 168 if (g == NULL) 169 err(1, "malloc"); 170 g->gid = grp->gr_gid; 171 g->name = name; 172 g->mem = (char **)malloc(i + 1); 173 if (g->mem == NULL) 174 err(1, "malloc"); 175 for (i = 0; grp->gr_mem[i] != NULL; i++) { 176 g->mem[i] = strdup(grp->gr_mem[i]); 177 if (g->mem[i] == NULL) 178 err(1, "malloc"); 179 } 180 g->mem[i] = NULL; 181 g->next = grouplist; 182 grouplist = g; 183 } 184 185 void 186 makemsg(const char *fname) 187 { 188 int ch, cnt; 189 struct tm *lt; 190 struct passwd *pw; 191 struct stat sbuf; 192 time_t now; 193 FILE *fp; 194 int fd; 195 const char *whom; 196 char *p, *tty, tmpname[MAXPATHLEN], lbuf[100], 197 hostname[MAXHOSTNAMELEN+1]; 198 199 (void)snprintf(tmpname, sizeof tmpname, "%s/wall.XXXXXX", _PATH_TMP); 200 if ((fd = mkstemp(tmpname)) == -1) 201 err(1, "can't open temporary file"); 202 (void)unlink(tmpname); 203 if (!(fp = fdopen(fd, "r+"))) 204 err(1, "can't open temporary file"); 205 206 if (!nobanner) { 207 if (!(whom = getlogin())) 208 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???"; 209 (void)gethostname(hostname, sizeof(hostname)); 210 hostname[sizeof(hostname) - 1] = '\0'; 211 (void)time(&now); 212 lt = localtime(&now); 213 214 /* 215 * all this stuff is to blank out a square for the message; 216 * we wrap message lines at column 79, not 80, because some 217 * terminals wrap after 79, some do not, and we can't tell. 218 * Which means that we may leave a non-blank character 219 * in column 80, but that can't be helped. 220 */ 221 (void)fprintf(fp, "\r%79s\r\n", " "); 222 (void)snprintf(lbuf, sizeof lbuf, 223 "Broadcast Message from %s@%s", whom, hostname); 224 (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf); 225 tty = ttyname(STDERR_FILENO); 226 if (tty == NULL) 227 tty = "??"; 228 (void)snprintf(lbuf, sizeof lbuf, 229 " (%s) at %d:%02d %s...", tty, 230 lt->tm_hour, lt->tm_min, lt->tm_zone); 231 (void)fprintf(fp, "%-79.79s\r\n", lbuf); 232 } 233 (void)fprintf(fp, "%79s\r\n", " "); 234 235 if (fname && !(freopen(fname, "r", stdin))) 236 err(1, "can't read %s", fname); 237 while (fgets(lbuf, sizeof(lbuf), stdin)) 238 for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) { 239 if (cnt == 79 || ch == '\n') { 240 for (; cnt < 79; ++cnt) 241 putc(' ', fp); 242 putc('\r', fp); 243 putc('\n', fp); 244 cnt = -1; 245 } 246 if (ch != '\n') 247 putc(ch, fp); 248 } 249 (void)fprintf(fp, "%79s\r\n", " "); 250 rewind(fp); 251 252 if (fstat(fd, &sbuf)) 253 err(1, "can't stat temporary file"); 254 if (sbuf.st_size > SIZE_T_MAX) 255 errx(1, "file too big"); 256 mbufsize = sbuf.st_size; 257 if (!(mbuf = malloc(mbufsize))) 258 err(1, "malloc"); 259 if (fread(mbuf, 1, mbufsize, fp) != mbufsize) 260 err(1, "can't read temporary file"); 261 (void)fclose(fp); 262 } 263 264 void 265 usage(void) 266 { 267 268 (void)fprintf(stderr, "usage: %s [-g group] [file]\n", getprogname()); 269 exit(1); 270 } 271
Indexes created Sat Nov 01 05:10:12 GMT 2025