Replaces commands/write. No Minix-specific changes needed.
The NetBSD version lacks a few features that were present
in the Minix version: cbreak mode, verbose, and shell escapes,
but the main write(1) functionality is there and working.
Change-Id: I87b9589c54d3595d26247d221bb3d1f613feeb8c
telnetd term termcap tget time touch \
truncate tty udpstat umount uname \
unstack update uud uue version vol \
- whereis which write writeisofs fetch \
+ whereis which writeisofs fetch \
zdump zmodem pkgin_cd pkgin_all \
worldstone updateboot update_bootcfg \
atnormalize dosread fdisk loadfont \
+++ /dev/null
-PROG= write
-BINGRP= tty
-BINMODE= 2755
-MAN=
-
-.include <bsd.prog.mk>
+++ /dev/null
-/* write - write to a logged in user Authors: N. Andrew and F. van Kempen */
-
-/*
- * Usage: write [-c] [-v] user [tty]
- * -c Read & write one character at a time (cbreak mode)
- * -v Verbose
- *
- * Version: 1.6 10/24/92
- *
- * NOTES: Write requires 1.4a (or higher) libraries,
- * for getopt(), strchr().
- *
- * Authors: Nick Andrew (nick@nswitgould.oz) - Public Domain
- * Fred van Kempen (minixug!waltje@kyber.uucp)
- */
-
-#include <sys/types.h>
-#include <fcntl.h>
-#include <pwd.h>
-#include <termios.h>
-#include <signal.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <utmp.h>
-#include <time.h>
-#include <stdio.h>
-#include <paths.h>
-
-#if 0
-static char *Version = "@(#) WRITE 1.6 (10/24/92)";
-#endif
-
-int otty; /* file desc of callee's terminal */
-short int cbreak = 0; /* are we in CBREAK (-c) mode? */
-short int verbose = 0; /* are we in VERBOSE (-v) mode? */
-short int writing = 0; /* is there a connection? */
-char *user = NULL; /* callee's user name */
-char *tty = NULL; /* callee's terminal if given */
-char *ourtty = NULL; /* our terminal name */
-struct termios ttyold, ttynew; /* our tty controlling structs */
-
-extern int optind;
-
-int main(int argc, char **argv);
-char *finduser(void);
-void settty(char *utty);
-void sayhello(void);
-void escape(char *cmd);
-void writetty(void);
-void usage(void);
-void intr(int dummy);
-
-char *finduser()
-{
-/* Search the UTMP database for the user we want. */
-
- static char utmptty[16];
- struct utmp utmp;
- struct passwd *userptr;
- int utmpfd;
-
- ourtty = ttyname(0);
- if (ourtty == NULL) ourtty = "/dev/console";
-
- if (user == NULL) exit(-1);
- if ((userptr = getpwnam(user)) == NULL) {
- fprintf(stderr, "No such user: %s\n", user);
- return(NULL);
- }
- if (verbose) fprintf(stderr, "Trying to write to %s\n",
- userptr->pw_gecos);
-
- if ((utmpfd = open(_PATH_UTMP, O_RDONLY)) < 0) {
- fprintf(stderr, "Cannot open utmp file\n");
- return(NULL);
- }
- utmptty[0] = '\0';
-
- /* We want to find if 'user' is logged on, and return in utmptty[]
- * 'user' `s terminal, and if 'user' is logged onto the tty the
- * caller specified, return that tty name. */
- while (read(utmpfd, (char *) &utmp, sizeof(utmp)) == sizeof(utmp)) {
- /* is this the user we are looking for? */
- if (strncmp(utmp.ut_name, user, sizeof(utmp.ut_name))) continue;
-
- strcpy(utmptty, utmp.ut_line);
- /* is he on the terminal we want to write to? */
- if (tty == NULL || !strcmp(utmptty, tty)) {
- break;
- }
- }
-
- if (utmptty[0] == '\0') {
- fprintf(stderr, "%s is not logged on\n", user);
- return( NULL);
- }
- if (tty != NULL && strcmp(utmptty, tty)) {
- fprintf(stderr, "%s is logged onto %s, not %s\n", user, utmptty, tty);
- return( NULL);
- }
- close(utmpfd);
-
- if (verbose) fprintf(stderr, "Writing to %s on %s\n", user, utmptty);
- return(utmptty);
-}
-
-
-void settty(utty)
-char *utty; /* name of terminal found in utmp */
-{
-/* Open other person's terminal and setup our own terminal. */
-
- char buff[48];
-
- sprintf(buff, "/dev/%s", utty);
- if ((otty = open(buff, O_WRONLY)) < 0) {
- fprintf(stderr, "Cannot open %s to write to %s\n", utty, user);
- fprintf(stderr, "It may have write permission turned off\n");
- exit(-1);
- }
- tcgetattr(0, &ttyold);
- tcgetattr(0, &ttynew);
- ttynew.c_lflag &= ~(ICANON|ECHO);
- signal(SIGINT, intr);
- if (cbreak) tcsetattr(0, TCSANOW, &ttynew);
-}
-
-
-void sayhello()
-{
- struct passwd *pw;
- char buff[128];
- time_t now;
- char *sp;
-
- time(&now);
-
- pw = getpwuid(getuid());
- if (pw == NULL) {
- fprintf(stderr, "unknown user\n");
- exit(-1);
- }
- if ((sp = strrchr(ourtty, '/')) != NULL)
- ++sp;
- else
- sp = ourtty;
-
- sprintf(buff, "\nMessage from %s (%s) %-24.24s...\n",
- pw->pw_name, sp, ctime(&now));
-
- write(otty, buff, strlen(buff));
- printf("\007\007");
- fflush(stdout);
-}
-
-
-void escape(cmd)
-char *cmd;
-{
-/* Shell escape. */
-
- register char *x;
-
- write(1, "!\n", 2);
- for (x = cmd; *x; ++x)
- if (*x == '\n') *x = '\0';
-
- system(cmd);
- write(1, "!\n", 2);
-}
-
-
-void writetty()
-{
-/* The write loop. */
-
- char line[80];
- int n, cb_esc;
-
- writing = 1;
- cb_esc = 0;
-
- while ((n = read(0, line, 79)) > 0) {
- if (line[0] == '\004') break; /* EOT */
-
- if (cbreak && line[0] == '\n') cb_esc = 1;
-
- if (cbreak) write(1, line, n);
-
- if (line[0] == '!') {
- if (cbreak && cb_esc) {
- cb_esc = 0;
- tcsetattr(0, TCSANOW, &ttyold);
- read(0, line, 79);
- escape(line);
- tcsetattr(0, TCSANOW, &ttynew);
- } else if (cbreak)
- write(otty, line, n);
- else
- escape(&line[1]);
- continue;
- }
- write(otty, line, n);
- }
- write(1, "\nEOT\n", 5);
- write(otty, "\nEOT\n", 5);
-}
-
-
-void usage()
-{
- fprintf(stderr, "usage: write [-c] [-v] user [tty]\n");
- fprintf(stderr, "\t-c : cbreak mode\n\t-v : verbose\n");
- exit(-1);
-}
-
-
-int main(argc, argv)
-int argc;
-char *argv[];
-{
- register int c;
- char *sp;
-
- setbuf(stdout, (char *) NULL);
-
- /* Parse options. */
- while ((c = getopt(argc, argv, "cv")) != EOF) switch (c) {
- case 'c': cbreak = 1; break;
- case 'v': verbose = 1; break;
- default:
- usage();
- }
-
- /* Parse user and tty arguments */
- if (optind < argc) {
- user = argv[optind++];
-
- /* WTMP usernames are 1-8 chars */
- if (strlen(user) > 8) *(user + 8) = '\0';
-
- if (optind < argc) {
- tty = argv[optind++];
- if (optind < argc) usage();
- }
- } else
- usage();
-
- sp = finduser(); /* find which tty to write onto */
- if (sp != NULL) { /* did we find one? */
- settty(sp); /* setup our terminal */
- sayhello(); /* print the initial message */
- writetty(); /* the write loop */
- tcsetattr(0, TCSANOW, &ttyold);
- exit(0);
- }
- return(-1);
-}
-
-void intr(dummy)
-int dummy; /* to satisfy the prototype */
-{
-/* The interrupt key has been hit. exit cleanly. */
-
- signal(SIGINT, SIG_IGN);
- fprintf(stderr, "\nInterrupt. Exiting write\n");
- tcsetattr(0, TCSANOW, &ttyold);
- if (writing) write(otty, "\nEOT\n", 5);
- exit(0);
-}
term.1 termcap.1 tget.1 time.1 true.1 \
truncate.1 tty.1 umount.1 uname.1 \
uud.1 uue.1 vol.1 whereis.1 which.1 \
- write.1 yap.1 linkfarm.1 pkg_view.1
+ yap.1 linkfarm.1 pkg_view.1
MLINKS += ash.1 sh.1
MLINKS += ash.1 ..1
+++ /dev/null
-.TH WRITE 1
-.SH NAME
-write \- send a message to a logged-in user
-.SH SYNOPSIS
-\fBwrite\fR [\fB\-cv\fR] \fIuser\fR [\fItty\fR]\fR
-.br
-.de FL
-.TP
-\\fB\\$1\\fR
-\\$2
-..
-.de EX
-.TP 20
-\\fB\\$1\\fR
-# \\$2
-..
-.SH OPTIONS
-.TP 5
-.B \-c
-# Use cbreak mode
-.TP 5
-.B \-v
-# Verbose mode
-.SH EXAMPLES
-.TP 20
-.B write ast
-# Send a message to ast
-.TP 20
-.B write ast tty00
-# Send a message to ast on tty00
-.SH DESCRIPTION
-.PP
-\fIWrite\fR lets a user send messages to another logged-in user.
-Lines typed by the user appear on the other user's screen a line at a time
-(a character at a time in the case of cbreak mode).
-The file \fI/usr/adm/wtmp\fR is searched to determine which tty to send to.
-If the user is logged onto more than one terminal, the \fItty\fR argument
-selects the terminal. Type CTRL- D to terminate the command.
-Use ! as a shell escape.
-.SH "SEE ALSO"
-.BR mail (1).
2012/10/17 12:00:00,usr.bin/wc
2013/03/22 12:00:00,usr.bin/whatis
2013/03/15 12:00:00,usr.bin/who
+2012/10/17 12:00:00,usr.bin/write
2012/10/17 12:00:00,usr.bin/xinstall
2013/03/15 12:00:00,usr.bin/yes
2012/02/10 16:16:12,usr.sbin/chroot
uuidgen \
\
wc whatis who \
- xargs xinstall yes
+ write xargs xinstall yes
.if !defined(__MINIX)
SUBDIR+= ../external/zlib/pigz/bin/pigz
--- /dev/null
+# $NetBSD: Makefile,v 1.8 2007/05/28 12:06:33 tls Exp $
+# from: @(#)Makefile 8.1 (Berkeley) 6/6/93
+
+.include <bsd.own.mk>
+
+USE_FORT?= yes # setgid
+PROG= write
+SRCS= write.c utmpentry.c term_chk.c
+BINMODE=2555
+BINGRP= tty
+
+.PATH.c: ${NETBSDSRCDIR}/usr.bin/who
+CPPFLAGS+=-I${NETBSDSRCDIR}/usr.bin/who -DSUPPORT_UTMPX -DSUPPORT_UTMP
+
+.include <bsd.prog.mk>
--- /dev/null
+/* $NetBSD: term_chk.c,v 1.8 2009/04/14 07:59:17 lukem Exp $ */
+
+/*
+ * Copyright (c) 1989, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jef Poskanzer and Craig Leres of the Lawrence Berkeley Laboratory.
+ *
+ * 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/cdefs.h>
+#ifndef lint
+__RCSID("$NetBSD: term_chk.c,v 1.8 2009/04/14 07:59:17 lukem Exp $");
+#endif
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <time.h>
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <paths.h>
+#include <fcntl.h>
+#include <string.h>
+#include <err.h>
+
+#include "term_chk.h"
+
+/*
+ * term_chk - check that a terminal exists, and get the message bit
+ * and the access time
+ */
+int
+term_chk(uid_t uid, const char *tty, int *msgsokP, time_t *atimeP, int ismytty,
+ gid_t saved_egid)
+{
+ char path[MAXPATHLEN];
+ struct stat s;
+ int i, fd, serrno;
+
+ if (strstr(tty, "../") != NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+ i = snprintf(path, sizeof path, _PATH_DEV "%s", tty);
+ if (i < 0 || i >= (int)sizeof(path)) {
+ errno = ENOMEM;
+ return -1;
+ }
+
+ (void)setegid(saved_egid);
+ fd = open(path, O_WRONLY, 0);
+ serrno = errno;
+ (void)setegid(getgid());
+ errno = serrno;
+
+ if (fd == -1)
+ return(-1);
+ if (fstat(fd, &s) == -1)
+ goto error;
+ if (!isatty(fd))
+ goto error;
+ if (s.st_uid != uid && uid != 0) {
+ errno = EPERM;
+ goto error;
+ }
+ if (msgsokP)
+ *msgsokP = (s.st_mode & S_IWGRP) != 0; /* group write bit */
+ if (atimeP)
+ *atimeP = s.st_atime;
+ if (ismytty)
+ (void)close(fd);
+ return ismytty ? 0 : fd;
+error:
+ if (fd != -1) {
+ serrno = errno;
+ (void)close(fd);
+ errno = serrno;
+ }
+ return -1;
+}
+
+char *
+check_sender(time_t *atime, uid_t myuid, gid_t saved_egid)
+{
+ int myttyfd;
+ int msgsok;
+ char *mytty;
+
+ /* check that sender has write enabled */
+ if (isatty(fileno(stdin)))
+ myttyfd = fileno(stdin);
+ else if (isatty(fileno(stdout)))
+ myttyfd = fileno(stdout);
+ else if (isatty(fileno(stderr)))
+ myttyfd = fileno(stderr);
+ else if (atime == NULL)
+ return NULL;
+ else
+ errx(1, "Cannot find your tty");
+ if ((mytty = ttyname(myttyfd)) == NULL)
+ err(1, "Cannot find the name of your tty");
+ if (strncmp(mytty, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
+ mytty += sizeof(_PATH_DEV) - 1;
+ if (term_chk(myuid, mytty, &msgsok, atime, 1, saved_egid) == -1)
+ err(1, "%s%s", _PATH_DEV, mytty);
+ if (!msgsok) {
+ warnx(
+ "You have write permission turned off; no reply possible");
+ }
+ return mytty;
+}
--- /dev/null
+/* $NetBSD: term_chk.h,v 1.2 2003/08/07 11:17:48 agc Exp $ */
+
+/*
+ * Copyright (c) 1989, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jef Poskanzer and Craig Leres of the Lawrence Berkeley Laboratory.
+ *
+ * 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.
+ */
+
+int term_chk(uid_t, const char *, int *, time_t *, int, gid_t);
+char *check_sender(time_t *, uid_t, gid_t);
--- /dev/null
+.\" $NetBSD: write.1,v 1.6 2003/08/07 11:17:48 agc Exp $
+.\"
+.\" Copyright (c) 1989, 1993
+.\" The Regents of the University of California. All rights reserved.
+.\"
+.\" This code is derived from software contributed to Berkeley by
+.\" Jef Poskanzer and Craig Leres of the Lawrence Berkeley Laboratory.
+.\"
+.\" 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.
+.\"
+.\" from: @(#)write.1 8.1 (Berkeley) 6/6/93
+.\"
+.Dd June 6, 1993
+.Dt WRITE 1
+.Os
+.Sh NAME
+.Nm write
+.Nd send a message to another user
+.Sh SYNOPSIS
+.Nm
+.Ar user
+.Op Ar ttyname
+.Sh DESCRIPTION
+.Nm
+allows you to communicate with other users, by copying lines from
+your terminal to theirs.
+.Pp
+When you run the
+.Nm
+command, the user you are writing to gets a message of the form:
+.Pp
+.Dl Message from yourname@yourhost on yourtty at hh:mm ...
+.Pp
+Any further lines you enter will be copied to the specified user's
+terminal.
+If the other user wants to reply, they must run
+.Nm
+as well.
+.Pp
+When you are done, type an end-of-file or interrupt character.
+The other user will see the message
+.Ql EOF
+indicating that the
+conversation is over.
+.Pp
+You can prevent people (other than the super-user) from writing to you
+with the
+.Xr mesg 1
+command.
+Some commands, for example
+.Xr nroff 1
+and
+.Xr pr 1 ,
+disallow writing automatically, so that your output isn't overwritten.
+.Pp
+If the user you want to write to is logged in on more than one terminal,
+you can specify which terminal to write to by specifying the terminal
+name as the second operand to the
+.Nm
+command.
+Alternatively, you can let
+.Nm
+select one of the terminals \- it will pick the one with the shortest
+idle time.
+This is so that if the user is logged in at work and also dialed up from
+home, the message will go to the right place.
+.Pp
+The traditional protocol for writing to someone is that the string
+.Ql \-o ,
+either at the end of a line or on a line by itself, means that it's the
+other person's turn to talk.
+The string
+.Ql oo
+means that the person believes the conversation to be
+over.
+.Sh SEE ALSO
+.Xr mesg 1 ,
+.Xr talk 1 ,
+.Xr who 1
+.Sh HISTORY
+A
+.Nm
+command appeared in
+.At v6 .
--- /dev/null
+/* $NetBSD: write.c,v 1.27 2011/09/06 18:46:35 joerg Exp $ */
+
+/*
+ * Copyright (c) 1989, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jef Poskanzer and Craig Leres of the Lawrence Berkeley Laboratory.
+ *
+ * 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/cdefs.h>
+#ifndef lint
+__COPYRIGHT("@(#) Copyright (c) 1989, 1993\
+ The Regents of the University of California. All rights reserved.");
+#endif /* not lint */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)write.c 8.2 (Berkeley) 4/27/95";
+#else
+__RCSID("$NetBSD: write.c,v 1.27 2011/09/06 18:46:35 joerg Exp $");
+#endif
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <time.h>
+#include <fcntl.h>
+#include <paths.h>
+#include <pwd.h>
+#include <unistd.h>
+#include <err.h>
+#include <errno.h>
+
+#include "utmpentry.h"
+#include "term_chk.h"
+
+__dead static void done(int);
+static void do_write(int, const char *, const uid_t);
+static void wr_fputs(char *);
+static int search_utmp(char *, char *, uid_t, gid_t);
+static int utmp_chk(const char *, const char *);
+
+int
+main(int argc, char **argv)
+{
+ time_t atime;
+ uid_t myuid, uid;
+ int msgsok, ttyfd;
+ char *mytty;
+ gid_t saved_egid = getegid();
+
+ if (setegid(getgid()) == -1)
+ err(1, "setegid");
+ myuid = getuid();
+ ttyfd = -1;
+
+ mytty = check_sender(&atime, myuid, saved_egid);
+
+ /* check args */
+ switch (argc) {
+ case 2:
+ ttyfd = search_utmp(argv[1], mytty, myuid, saved_egid);
+ break;
+ case 3:
+ if (!strncmp(argv[2], _PATH_DEV, strlen(_PATH_DEV)))
+ argv[2] += strlen(_PATH_DEV);
+ if (uid_from_user(argv[1], &uid) == -1)
+ errx(1, "%s: unknown user", argv[1]);
+ if (utmp_chk(argv[1], argv[2]))
+ errx(1, "%s is not logged in on %s",
+ argv[1], argv[2]);
+ ttyfd = term_chk(uid, argv[2], &msgsok, &atime, 0, saved_egid);
+ if (ttyfd == -1)
+ err(1, "%s%s", _PATH_DEV, argv[2]);
+ if (myuid && !msgsok)
+ errx(1, "%s has messages disabled on %s",
+ argv[1], argv[2]);
+ break;
+ default:
+ (void)fprintf(stderr, "usage: write user [tty]\n");
+ exit(1);
+ }
+ if (setgid(getgid()) == -1)
+ err(1, "setgid");
+ do_write(ttyfd, mytty, myuid);
+ done(0);
+ /* NOTREACHED */
+#ifdef __GNUC__
+ return (0);
+#endif
+}
+
+/*
+ * utmp_chk - checks that the given user is actually logged in on
+ * the given tty
+ */
+static int
+utmp_chk(const char *user, const char *tty)
+{
+ struct utmpentry *ep;
+
+ (void)getutentries(NULL, &ep);
+
+ for (; ep; ep = ep->next)
+ if (strcmp(user, ep->name) == 0 && strcmp(tty, ep->line) == 0)
+ return(0);
+ return(1);
+}
+
+/*
+ * search_utmp - search utmp for the "best" terminal to write to
+ *
+ * Ignores terminals with messages disabled, and of the rest, returns
+ * the one with the most recent access time. Returns as value the number
+ * of the user's terminals with messages enabled, or -1 if the user is
+ * not logged in at all.
+ *
+ * Special case for writing to yourself - ignore the terminal you're
+ * writing from, unless that's the only terminal with messages enabled.
+ */
+static int
+search_utmp(char *user, char *mytty, uid_t myuid, gid_t saved_egid)
+{
+ char tty[MAXPATHLEN];
+ time_t bestatime, atime;
+ int nloggedttys, nttys, msgsok, user_is_me;
+ struct utmpentry *ep;
+ int fd, nfd;
+ uid_t uid;
+
+ if (uid_from_user(user, &uid) == -1)
+ errx(1, "%s: unknown user", user);
+
+ (void)getutentries(NULL, &ep);
+
+ nloggedttys = nttys = 0;
+ bestatime = 0;
+ user_is_me = 0;
+ fd = -1;
+ for (; ep; ep = ep->next)
+ if (strcmp(user, ep->name) == 0) {
+ ++nloggedttys;
+ nfd = term_chk(uid, ep->line, &msgsok, &atime, 0,
+ saved_egid);
+ if (nfd == -1)
+ continue; /* bad term? skip */
+ if (myuid && !msgsok) {
+ close(nfd);
+ continue; /* skip ttys with msgs off */
+ }
+ if (strcmp(ep->line, mytty) == 0) {
+ user_is_me = 1;
+ if (fd == -1)
+ fd = nfd;
+ else
+ close(nfd);
+ continue; /* don't write to yourself */
+ }
+ ++nttys;
+ if (atime > bestatime) {
+ bestatime = atime;
+ (void)strlcpy(tty, ep->line, sizeof(tty));
+ close(fd);
+ fd = nfd;
+ } else
+ close(nfd);
+ }
+
+ if (nloggedttys == 0)
+ errx(1, "%s is not logged in", user);
+ if (nttys == 0) {
+ if (user_is_me) /* ok, so write to yourself! */
+ return fd;
+ errx(1, "%s has messages disabled", user);
+ } else if (nttys > 1)
+ warnx("%s is logged in more than once; writing to %s",
+ user, tty);
+ return fd;
+}
+
+/*
+ * do_write - actually make the connection
+ */
+static void
+do_write(int ttyfd, const char *mytty, const uid_t myuid)
+{
+ const char *login;
+ char *nows;
+ struct passwd *pwd;
+ time_t now;
+ char host[MAXHOSTNAMELEN + 1], line[512];
+
+ /* Determine our login name before we re-open stdout */
+ if ((login = getlogin()) == NULL) {
+ if ((pwd = getpwuid(myuid)) != NULL)
+ login = pwd->pw_name;
+ else login = "???";
+ }
+
+ if (dup2(ttyfd, STDOUT_FILENO) == -1)
+ err(1, "dup2");
+
+ (void)signal(SIGINT, done);
+ (void)signal(SIGHUP, done);
+ (void)close(ttyfd);
+
+ /* print greeting */
+ if (gethostname(host, sizeof(host)) < 0)
+ (void)strlcpy(host, "???", sizeof(host));
+ else
+ host[sizeof(host) - 1] = '\0';
+ now = time(NULL);
+ nows = ctime(&now);
+ nows[16] = '\0';
+ (void)printf("\r\n\a\a\aMessage from %s@%s on %s at %s ...\r\n",
+ login, host, mytty, nows + 11);
+
+ while (fgets(line, sizeof(line), stdin) != NULL)
+ wr_fputs(line);
+}
+
+/*
+ * done - cleanup and exit
+ */
+static void
+done(int signo)
+{
+
+ (void)write(STDOUT_FILENO, "EOF\r\n", sizeof("EOF\r\n") - 1);
+ if (signo == 0)
+ exit(0);
+ else
+ _exit(0);
+}
+
+/*
+ * wr_fputs - like fputs(), but makes control characters visible and
+ * turns \n into \r\n
+ */
+static void
+wr_fputs(char *s)
+{
+ unsigned char c;
+
+#define PUTC(c) if (putchar(c) == EOF) goto err;
+
+ for (; *s != '\0'; ++s) {
+ c = toascii(*s);
+ if (c == '\n') {
+ PUTC('\r');
+ } else if (!isprint(c) && !isspace(c) && c != '\a') {
+ PUTC('^');
+ c ^= 0x40; /* DEL to ?, others to alpha */
+ }
+ PUTC(c);
+ }
+ return;
+
+err: err(1, NULL);
+#undef PUTC
+}