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Diffstat (limited to 'term-utils/ttymsg.c')
| -rw-r--r-- | term-utils/ttymsg.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/term-utils/ttymsg.c b/term-utils/ttymsg.c new file mode 100644 index 0000000..faa0344 --- /dev/null +++ b/term-utils/ttymsg.c @@ -0,0 +1,192 @@ +/* + * 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. + * + * Modified Sun Mar 12 10:39:22 1995, faith@cs.unc.edu for Linux + * + */ + + /* 1999-02-22 Arkadiusz Miśkiewicz <misiek@pld.ORG.PL> + * - added Native Language Support + * Sun Mar 21 1999 - Arnaldo Carvalho de Melo <acme@conectiva.com.br> + * - fixed strerr(errno) in gettext calls + */ + +#include <sys/types.h> +#include <sys/param.h> +#include <sys/uio.h> +#include <signal.h> +#include <fcntl.h> +#include <dirent.h> +#include <errno.h> +#include <paths.h> +#include <unistd.h> +#include <stdio.h> +#include <string.h> +#include <stdlib.h> + +#include "nls.h" +#include "closestream.h" +#include "pathnames.h" +#include "ttymsg.h" + +#define ERR_BUFLEN (MAXNAMLEN + 1024) + +/* + * 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.). + */ +char * +ttymsg(struct iovec *iov, size_t iovcnt, char *line, int tmout) { + static char device[MAXNAMLEN]; + static char errbuf[ERR_BUFLEN]; + size_t cnt, left; + ssize_t wret; + struct iovec localiov[6]; + int fd, forked = 0; + ssize_t len = 0; + + if (iovcnt > ARRAY_SIZE(localiov)) { + snprintf(errbuf, sizeof(errbuf), _("internal error: too many iov's")); + return errbuf; + } + + /* The old code here rejected the line argument when it contained a '/', + saying: "A slash may be an attempt to break security...". + However, if a user can control the line argument here + then they can make this routine write to /dev/hda or /dev/sda + already. So, this test was worthless, and these days it is + also wrong since people use /dev/pts/xxx. */ + + len = snprintf(device, sizeof(device), "%s%s", _PATH_DEV, line); + if (len < 0 || (size_t)len >= sizeof(device)) { + snprintf(errbuf, sizeof(errbuf), _("excessively long line arg")); + 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 || errno == ENOENT) + return NULL; + + len = snprintf(errbuf, sizeof(errbuf), "%s: %m", device); + if (len < 0 || (size_t)len >= sizeof(errbuf)) + snprintf(errbuf, sizeof(errbuf), _("open failed")); + return errbuf; + } + + for (cnt = left = 0; cnt < iovcnt; ++cnt) + left += iov[cnt].iov_len; + + for (;;) { + wret = writev(fd, iov, iovcnt); + if (wret >= (ssize_t) left) + break; + if (wret >= 0) { + left -= wret; + if (iov != localiov) { + memmove(localiov, iov, + iovcnt * sizeof(struct iovec)); + iov = localiov; + } + for (cnt = 0; wret >= (ssize_t) 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, flags; + sigset_t sigmask; + + if (forked) { + close(fd); + _exit(EXIT_FAILURE); + } + cpid = fork(); + if (cpid < 0) { + len = snprintf(errbuf, sizeof(errbuf), _("fork: %m")); + if (len < 0 || (size_t)len >= sizeof(errbuf)) + snprintf(errbuf, sizeof(errbuf), _("cannot fork")); + close(fd); + return errbuf; + } + if (cpid) { /* parent */ + close(fd); + return NULL; + } + forked++; + /* wait at most tmout seconds */ + signal(SIGALRM, SIG_DFL); + signal(SIGTERM, SIG_DFL); /* XXX */ + sigemptyset(&sigmask); + sigprocmask (SIG_SETMASK, &sigmask, NULL); + alarm((u_int)tmout); + flags = fcntl(fd, F_GETFL); + fcntl(flags, F_SETFL, (long) (flags & ~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; + if (close_fd(fd) != 0) + warn(_("write failed: %s"), device); + if (forked) + _exit(EXIT_FAILURE); + + len = snprintf(errbuf, sizeof(errbuf), "%s: %m", device); + if (len < 0 || (size_t)len >= sizeof(errbuf)) + snprintf(errbuf, sizeof(errbuf), + _("%s: BAD ERROR, message is " + "far too long"), device); + return errbuf; + } + + close(fd); + + if (forked) + _exit(EXIT_SUCCESS); + return NULL; +} |