19b50d902SRodney W. Grimes /* 29b50d902SRodney W. Grimes * Copyright (c) 1989, 1993 39b50d902SRodney W. Grimes * The Regents of the University of California. All rights reserved. 49b50d902SRodney W. Grimes * 59b50d902SRodney W. Grimes * Redistribution and use in source and binary forms, with or without 69b50d902SRodney W. Grimes * modification, are permitted provided that the following conditions 79b50d902SRodney W. Grimes * are met: 89b50d902SRodney W. Grimes * 1. Redistributions of source code must retain the above copyright 99b50d902SRodney W. Grimes * notice, this list of conditions and the following disclaimer. 109b50d902SRodney W. Grimes * 2. Redistributions in binary form must reproduce the above copyright 119b50d902SRodney W. Grimes * notice, this list of conditions and the following disclaimer in the 129b50d902SRodney W. Grimes * documentation and/or other materials provided with the distribution. 139b50d902SRodney W. Grimes * 3. All advertising materials mentioning features or use of this software 149b50d902SRodney W. Grimes * must display the following acknowledgement: 159b50d902SRodney W. Grimes * This product includes software developed by the University of 169b50d902SRodney W. Grimes * California, Berkeley and its contributors. 179b50d902SRodney W. Grimes * 4. Neither the name of the University nor the names of its contributors 189b50d902SRodney W. Grimes * may be used to endorse or promote products derived from this software 199b50d902SRodney W. Grimes * without specific prior written permission. 209b50d902SRodney W. Grimes * 219b50d902SRodney W. Grimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 229b50d902SRodney W. Grimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 239b50d902SRodney W. Grimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 249b50d902SRodney W. Grimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 259b50d902SRodney W. Grimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 269b50d902SRodney W. Grimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 279b50d902SRodney W. Grimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 289b50d902SRodney W. Grimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 299b50d902SRodney W. Grimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 309b50d902SRodney W. Grimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 319b50d902SRodney W. Grimes * SUCH DAMAGE. 329b50d902SRodney W. Grimes */ 339b50d902SRodney W. Grimes 349b50d902SRodney W. Grimes #ifndef lint 359b50d902SRodney W. Grimes static char sccsid[] = "@(#)ttymsg.c 8.2 (Berkeley) 11/16/93"; 369b50d902SRodney W. Grimes #endif /* not lint */ 379b50d902SRodney W. Grimes 389b50d902SRodney W. Grimes #include <sys/types.h> 399b50d902SRodney W. Grimes #include <sys/uio.h> 409b50d902SRodney W. Grimes #include <signal.h> 419b50d902SRodney W. Grimes #include <fcntl.h> 429b50d902SRodney W. Grimes #include <dirent.h> 439b50d902SRodney W. Grimes #include <errno.h> 449b50d902SRodney W. Grimes #include <paths.h> 459b50d902SRodney W. Grimes #include <unistd.h> 469b50d902SRodney W. Grimes #include <stdio.h> 479b50d902SRodney W. Grimes #include <string.h> 489b50d902SRodney W. Grimes #include <stdlib.h> 499b50d902SRodney W. Grimes 509b50d902SRodney W. Grimes /* 519b50d902SRodney W. Grimes * Display the contents of a uio structure on a terminal. Used by wall(1), 529b50d902SRodney W. Grimes * syslogd(8), and talkd(8). Forks and finishes in child if write would block, 539b50d902SRodney W. Grimes * waiting up to tmout seconds. Returns pointer to error string on unexpected 549b50d902SRodney W. Grimes * error; string is not newline-terminated. Various "normal" errors are 559b50d902SRodney W. Grimes * ignored (exclusive-use, lack of permission, etc.). 569b50d902SRodney W. Grimes */ 579b50d902SRodney W. Grimes char * 589b50d902SRodney W. Grimes ttymsg(iov, iovcnt, line, tmout) 599b50d902SRodney W. Grimes struct iovec *iov; 609b50d902SRodney W. Grimes int iovcnt; 619b50d902SRodney W. Grimes char *line; 629b50d902SRodney W. Grimes int tmout; 639b50d902SRodney W. Grimes { 649b50d902SRodney W. Grimes static char device[MAXNAMLEN] = _PATH_DEV; 659b50d902SRodney W. Grimes static char errbuf[1024]; 669b50d902SRodney W. Grimes register int cnt, fd, left, wret; 679b50d902SRodney W. Grimes struct iovec localiov[6]; 689b50d902SRodney W. Grimes int forked = 0; 699b50d902SRodney W. Grimes 709b50d902SRodney W. Grimes if (iovcnt > sizeof(localiov) / sizeof(localiov[0])) 719b50d902SRodney W. Grimes return ("too many iov's (change code in wall/ttymsg.c)"); 729b50d902SRodney W. Grimes 739b50d902SRodney W. Grimes (void) strcpy(device + sizeof(_PATH_DEV) - 1, line); 749b50d902SRodney W. Grimes if (strchr(device + sizeof(_PATH_DEV) - 1, '/')) { 759b50d902SRodney W. Grimes /* A slash is an attempt to break security... */ 769b50d902SRodney W. Grimes (void) snprintf(errbuf, sizeof(errbuf), "'/' in \"%s\"", 779b50d902SRodney W. Grimes device); 789b50d902SRodney W. Grimes return (errbuf); 799b50d902SRodney W. Grimes } 809b50d902SRodney W. Grimes 819b50d902SRodney W. Grimes /* 829b50d902SRodney W. Grimes * open will fail on slip lines or exclusive-use lines 839b50d902SRodney W. Grimes * if not running as root; not an error. 849b50d902SRodney W. Grimes */ 859b50d902SRodney W. Grimes if ((fd = open(device, O_WRONLY|O_NONBLOCK, 0)) < 0) { 869b50d902SRodney W. Grimes if (errno == EBUSY || errno == EACCES) 879b50d902SRodney W. Grimes return (NULL); 889b50d902SRodney W. Grimes (void) snprintf(errbuf, sizeof(errbuf), 899b50d902SRodney W. Grimes "%s: %s", device, strerror(errno)); 909b50d902SRodney W. Grimes return (errbuf); 919b50d902SRodney W. Grimes } 929b50d902SRodney W. Grimes 939b50d902SRodney W. Grimes for (cnt = left = 0; cnt < iovcnt; ++cnt) 949b50d902SRodney W. Grimes left += iov[cnt].iov_len; 959b50d902SRodney W. Grimes 969b50d902SRodney W. Grimes for (;;) { 979b50d902SRodney W. Grimes wret = writev(fd, iov, iovcnt); 989b50d902SRodney W. Grimes if (wret >= left) 999b50d902SRodney W. Grimes break; 1009b50d902SRodney W. Grimes if (wret >= 0) { 1019b50d902SRodney W. Grimes left -= wret; 1029b50d902SRodney W. Grimes if (iov != localiov) { 1039b50d902SRodney W. Grimes bcopy(iov, localiov, 1049b50d902SRodney W. Grimes iovcnt * sizeof(struct iovec)); 1059b50d902SRodney W. Grimes iov = localiov; 1069b50d902SRodney W. Grimes } 1079b50d902SRodney W. Grimes for (cnt = 0; wret >= iov->iov_len; ++cnt) { 1089b50d902SRodney W. Grimes wret -= iov->iov_len; 1099b50d902SRodney W. Grimes ++iov; 1109b50d902SRodney W. Grimes --iovcnt; 1119b50d902SRodney W. Grimes } 1129b50d902SRodney W. Grimes if (wret) { 1139b50d902SRodney W. Grimes iov->iov_base += wret; 1149b50d902SRodney W. Grimes iov->iov_len -= wret; 1159b50d902SRodney W. Grimes } 1169b50d902SRodney W. Grimes continue; 1179b50d902SRodney W. Grimes } 1189b50d902SRodney W. Grimes if (errno == EWOULDBLOCK) { 1199b50d902SRodney W. Grimes int cpid, off = 0; 1209b50d902SRodney W. Grimes 1219b50d902SRodney W. Grimes if (forked) { 1229b50d902SRodney W. Grimes (void) close(fd); 1239b50d902SRodney W. Grimes _exit(1); 1249b50d902SRodney W. Grimes } 1259b50d902SRodney W. Grimes cpid = fork(); 1269b50d902SRodney W. Grimes if (cpid < 0) { 1279b50d902SRodney W. Grimes (void) snprintf(errbuf, sizeof(errbuf), 1289b50d902SRodney W. Grimes "fork: %s", strerror(errno)); 1299b50d902SRodney W. Grimes (void) close(fd); 1309b50d902SRodney W. Grimes return (errbuf); 1319b50d902SRodney W. Grimes } 1329b50d902SRodney W. Grimes if (cpid) { /* parent */ 1339b50d902SRodney W. Grimes (void) close(fd); 1349b50d902SRodney W. Grimes return (NULL); 1359b50d902SRodney W. Grimes } 1369b50d902SRodney W. Grimes forked++; 1379b50d902SRodney W. Grimes /* wait at most tmout seconds */ 1389b50d902SRodney W. Grimes (void) signal(SIGALRM, SIG_DFL); 1399b50d902SRodney W. Grimes (void) signal(SIGTERM, SIG_DFL); /* XXX */ 1409b50d902SRodney W. Grimes (void) sigsetmask(0); 1419b50d902SRodney W. Grimes (void) alarm((u_int)tmout); 1429b50d902SRodney W. Grimes (void) fcntl(fd, O_NONBLOCK, &off); 1439b50d902SRodney W. Grimes continue; 1449b50d902SRodney W. Grimes } 1459b50d902SRodney W. Grimes /* 1469b50d902SRodney W. Grimes * We get ENODEV on a slip line if we're running as root, 1479b50d902SRodney W. Grimes * and EIO if the line just went away. 1489b50d902SRodney W. Grimes */ 1499b50d902SRodney W. Grimes if (errno == ENODEV || errno == EIO) 1509b50d902SRodney W. Grimes break; 1519b50d902SRodney W. Grimes (void) close(fd); 1529b50d902SRodney W. Grimes if (forked) 1539b50d902SRodney W. Grimes _exit(1); 1549b50d902SRodney W. Grimes (void) snprintf(errbuf, sizeof(errbuf), 1559b50d902SRodney W. Grimes "%s: %s", device, strerror(errno)); 1569b50d902SRodney W. Grimes return (errbuf); 1579b50d902SRodney W. Grimes } 1589b50d902SRodney W. Grimes 1599b50d902SRodney W. Grimes (void) close(fd); 1609b50d902SRodney W. Grimes if (forked) 1619b50d902SRodney W. Grimes _exit(0); 1629b50d902SRodney W. Grimes return (NULL); 1639b50d902SRodney W. Grimes } 164