diff options
Diffstat (limited to 'usr.bin/wall/ttymsg.c')
| -rw-r--r-- | usr.bin/wall/ttymsg.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/usr.bin/wall/ttymsg.c b/usr.bin/wall/ttymsg.c new file mode 100644 index 0000000..37b09e9 --- /dev/null +++ b/usr.bin/wall/ttymsg.c @@ -0,0 +1,167 @@ +/* + * 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. + * 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 <sys/cdefs.h> + +__FBSDID("$FreeBSD$"); + +#ifndef lint +static const char sccsid[] = "@(#)ttymsg.c 8.2 (Berkeley) 11/16/93"; +#endif + +#include <sys/types.h> +#include <sys/uio.h> +#include <dirent.h> +#include <errno.h> +#include <fcntl.h> +#include <paths.h> +#include <signal.h> +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <unistd.h> + +#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]; + char *p; + int forked; + + forked = 0; + if (iovcnt > (int)(sizeof(localiov) / sizeof(localiov[0]))) + return ("too many iov's (change code in wall/ttymsg.c)"); + + p = device + sizeof(_PATH_DEV) - 1; + strlcpy(p, line, sizeof(device)); + if (strncmp(p, "pts/", 4) == 0) + p += 4; + if (strchr(p, '/') != NULL) { + /* 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); +} |
