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IABSD.fr/src/usr.sbin/syslogd/ttymsg.c
bluhm
- usr.sbin/syslogd/ttymsg.c
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/* $OpenBSD: ttymsg.c,v 1.19 2021/09/03 16:28:33 bluhm Exp $ */ /* $NetBSD: ttymsg.c,v 1.3 1994/11/17 07:17:55 jtc Exp $ */ /* * Copyright (c) 2014-2017 Alexander Bluhm <bluhm@genua.de> * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* * 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. 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 <sys/stat.h> #include <sys/syslog.h> #include <dirent.h> #include <errno.h> #include <event.h> #include <paths.h> #include <signal.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include "log.h" #include "syslogd.h" struct tty_delay { struct event td_event; size_t td_length; char td_line[LOG_MAXLINE]; }; int tty_delayed = 0; void ttycb(int, short, void *); /* * Display the contents of a uio structure on a terminal. * Schedules an event if write would block, waiting up to TTYMSGTIME * seconds. */ void ttymsg(char *utline, struct iovec *iov) { static char device[MAXNAMLEN] = _PATH_DEV; struct iovec localiov[IOVCNT]; int iovcnt = IOVCNT; int cnt, fd; size_t left; ssize_t wret; /* * Ignore lines that start with "ftp" or "uucp". */ if ((strncmp(utline, "ftp", 3) == 0) || (strncmp(utline, "uucp", 4) == 0)) return; (void) strlcpy(device + sizeof(_PATH_DEV) - 1, utline, sizeof(device) - (sizeof(_PATH_DEV) - 1)); if (strchr(device + sizeof(_PATH_DEV) - 1, '/')) { /* A slash is an attempt to break security... */ log_warnx("'/' in tty device \"%s\"", device); return; } /* * open will fail on slip lines or exclusive-use lines * if not running as root; not an error. */ if ((fd = priv_open_tty(device)) == -1) { if (errno != EBUSY && errno != EACCES) log_warn("priv_open_tty device \"%s\"", device); return; } left = 0; for (cnt = 0; cnt < iovcnt; ++cnt) left += iov[cnt].iov_len; for (;;) { wret = writev(fd, iov, iovcnt); if (wret >= 0) { if ((size_t)wret >= left) break; left -= wret; if (iov != localiov) { memmove(localiov, iov, iovcnt * sizeof(struct iovec)); iov = localiov; } while ((size_t)wret >= iov->iov_len) { wret -= iov->iov_len; ++iov; --iovcnt; } if (wret) { iov->iov_base = (char *)iov->iov_base + wret; iov->iov_len -= wret; } continue; } if (errno == EWOULDBLOCK) { struct tty_delay *td; struct timeval to; if (tty_delayed >= TTYMAXDELAY) { log_warnx("tty device \"%s\": %s", device, "too many delayed writes"); break; } log_debug("ttymsg delayed write"); if (iov != localiov) { memmove(localiov, iov, iovcnt * sizeof(struct iovec)); iov = localiov; } if ((td = malloc(sizeof(*td))) == NULL) { log_warn("allocate delay tty device \"%s\"", device); break; } td->td_length = 0; if (left > LOG_MAXLINE) left = LOG_MAXLINE; while (iovcnt && left) { if (iov->iov_len > left) iov->iov_len = left; memcpy(td->td_line + td->td_length, iov->iov_base, iov->iov_len); td->td_length += iov->iov_len; left -= iov->iov_len; ++iov; --iovcnt; } tty_delayed++; event_set(&td->td_event, fd, EV_WRITE, ttycb, td); to.tv_sec = TTYMSGTIME; to.tv_usec = 0; event_add(&td->td_event, &to); return; } /* * 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) log_warn("writev tty device \"%s\"", device); break; } (void) close(fd); return; } void ttycb(int fd, short event, void *arg) { struct tty_delay *td = arg; struct timeval to; ssize_t wret; if (event != EV_WRITE) goto done; wret = write(fd, td->td_line, td->td_length); if (wret == -1 && errno != EINTR && errno != EWOULDBLOCK) goto done; if (wret > 0) { td->td_length -= wret; if (td->td_length == 0) goto done; memmove(td->td_line, td->td_line + wret, td->td_length); } to.tv_sec = TTYMSGTIME; to.tv_usec = 0; event_add(&td->td_event, &to); return; done: tty_delayed--; close(fd); free(td); }