From: Thomas Cort Date: Fri, 25 Oct 2013 19:25:55 +0000 (-0400) Subject: Importing usr.bin/write X-Git-Tag: v3.3.0~731 X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/zpipe.c?a=commitdiff_plain;h=00709a7737e9715e29a192fe59a95679b88d2887;p=minix.git Importing usr.bin/write 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 --- diff --git a/commands/Makefile b/commands/Makefile index 45df0a654..35f06d9be 100644 --- a/commands/Makefile +++ b/commands/Makefile @@ -29,7 +29,7 @@ SUBDIR= add_route arp ash at backup btrace \ 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 \ diff --git a/commands/write/Makefile b/commands/write/Makefile deleted file mode 100644 index e1e0e19bd..000000000 --- a/commands/write/Makefile +++ /dev/null @@ -1,6 +0,0 @@ -PROG= write -BINGRP= tty -BINMODE= 2755 -MAN= - -.include diff --git a/commands/write/write.c b/commands/write/write.c deleted file mode 100644 index 335f49d68..000000000 --- a/commands/write/write.c +++ /dev/null @@ -1,271 +0,0 @@ -/* 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 -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#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); -} diff --git a/man/man1/Makefile b/man/man1/Makefile index da66405a1..dc31a2c11 100644 --- a/man/man1/Makefile +++ b/man/man1/Makefile @@ -21,7 +21,7 @@ MAN= ash.1 at.1 \ 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 diff --git a/man/man1/write.1 b/man/man1/write.1 deleted file mode 100644 index 6dd955d50..000000000 --- a/man/man1/write.1 +++ /dev/null @@ -1,41 +0,0 @@ -.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). diff --git a/releasetools/nbsd_ports b/releasetools/nbsd_ports index d0e7a5df1..31428cf93 100644 --- a/releasetools/nbsd_ports +++ b/releasetools/nbsd_ports @@ -214,6 +214,7 @@ 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 diff --git a/usr.bin/Makefile b/usr.bin/Makefile index 7655e1841..28b24327c 100644 --- a/usr.bin/Makefile +++ b/usr.bin/Makefile @@ -32,7 +32,7 @@ SUBDIR= \ uuidgen \ \ wc whatis who \ - xargs xinstall yes + write xargs xinstall yes .if !defined(__MINIX) SUBDIR+= ../external/zlib/pigz/bin/pigz diff --git a/usr.bin/write/Makefile b/usr.bin/write/Makefile new file mode 100644 index 000000000..843943998 --- /dev/null +++ b/usr.bin/write/Makefile @@ -0,0 +1,15 @@ +# $NetBSD: Makefile,v 1.8 2007/05/28 12:06:33 tls Exp $ +# from: @(#)Makefile 8.1 (Berkeley) 6/6/93 + +.include + +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 diff --git a/usr.bin/write/term_chk.c b/usr.bin/write/term_chk.c new file mode 100644 index 000000000..d7d2cbe04 --- /dev/null +++ b/usr.bin/write/term_chk.c @@ -0,0 +1,137 @@ +/* $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 +#ifndef lint +__RCSID("$NetBSD: term_chk.c,v 1.8 2009/04/14 07:59:17 lukem Exp $"); +#endif + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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; +} diff --git a/usr.bin/write/term_chk.h b/usr.bin/write/term_chk.h new file mode 100644 index 000000000..aca456838 --- /dev/null +++ b/usr.bin/write/term_chk.h @@ -0,0 +1,36 @@ +/* $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); diff --git a/usr.bin/write/write.1 b/usr.bin/write/write.1 new file mode 100644 index 000000000..28d614c38 --- /dev/null +++ b/usr.bin/write/write.1 @@ -0,0 +1,106 @@ +.\" $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 . diff --git a/usr.bin/write/write.c b/usr.bin/write/write.c new file mode 100644 index 000000000..945e92fe5 --- /dev/null +++ b/usr.bin/write/write.c @@ -0,0 +1,292 @@ +/* $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 +#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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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 +}