/* * Copyright (c) 1989, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #ifndef lint static const char sccsid[] = "@(#)ttymsg.c 8.2 (Berkeley) 11/16/93"; #endif #include #include #include #include #include #include #include #include #include #include #include #include "ttymsg.h" /* * Display the contents of a uio structure on a terminal. Used by wall(1), * syslogd(8), and talkd(8). Forks and finishes in child if write would block, * waiting up to tmout seconds. Returns pointer to error string on unexpected * error; string is not newline-terminated. Various "normal" errors are * ignored (exclusive-use, lack of permission, etc.). */ const char * ttymsg(struct iovec *iov, int iovcnt, const char *line, int tmout) { struct iovec localiov[7]; ssize_t left, wret; int cnt, fd; static char device[MAXNAMLEN] = _PATH_DEV; static char errbuf[1024]; int forked; forked = 0; if (iovcnt > (int)(sizeof(localiov) / sizeof(localiov[0]))) return ("too many iov's (change code in wall/ttymsg.c)"); strlcpy(device + sizeof(_PATH_DEV) - 1, line, sizeof(device)); if (strchr(device + sizeof(_PATH_DEV) - 1, '/')) { /* A slash is an attempt to break security... */ (void) snprintf(errbuf, sizeof(errbuf), "Too many '/' in \"%s\"", device); return (errbuf); } /* * open will fail on slip lines or exclusive-use lines * if not running as root; not an error. */ if ((fd = open(device, O_WRONLY|O_NONBLOCK, 0)) < 0) { if (errno == EBUSY || errno == EACCES) return (NULL); (void) snprintf(errbuf, sizeof(errbuf), "%s: %s", device, strerror(errno)); return (errbuf); } for (cnt = 0, left = 0; cnt < iovcnt; ++cnt) left += iov[cnt].iov_len; for (;;) { wret = writev(fd, iov, iovcnt); if (wret >= left) break; if (wret >= 0) { left -= wret; if (iov != localiov) { bcopy(iov, localiov, iovcnt * sizeof(struct iovec)); iov = localiov; } for (cnt = 0; (size_t)wret >= iov->iov_len; ++cnt) { wret -= iov->iov_len; ++iov; --iovcnt; } if (wret) { iov->iov_base = (char *)iov->iov_base + wret; iov->iov_len -= wret; } continue; } if (errno == EWOULDBLOCK) { int cpid; if (forked) { (void) close(fd); _exit(1); } cpid = fork(); if (cpid < 0) { (void) snprintf(errbuf, sizeof(errbuf), "fork: %s", strerror(errno)); (void) close(fd); return (errbuf); } if (cpid) { /* parent */ (void) close(fd); return (NULL); } forked++; /* wait at most tmout seconds */ (void) signal(SIGALRM, SIG_DFL); (void) signal(SIGTERM, SIG_DFL); /* XXX */ (void) sigsetmask(0); (void) alarm((u_int)tmout); (void) fcntl(fd, F_SETFL, 0); /* clear O_NONBLOCK */ continue; } /* * We get ENODEV on a slip line if we're running as root, * and EIO if the line just went away. */ if (errno == ENODEV || errno == EIO) break; (void) close(fd); if (forked) _exit(1); (void) snprintf(errbuf, sizeof(errbuf), "%s: %s", device, strerror(errno)); return (errbuf); } (void) close(fd); if (forked) _exit(0); return (NULL); }