From 5b57d28ffb6e1ef86b50f7d05d977826eae89bfe Mon Sep 17 00:00:00 2001 From: Kiyoshi Aman Date: Fri, 1 Feb 2019 22:55:37 +0000 Subject: initial population --- usr.bin/write/term_chk.c | 137 ++++++++++++++++++++++ usr.bin/write/term_chk.h | 36 ++++++ usr.bin/write/write.1 | 106 +++++++++++++++++ usr.bin/write/write.c | 292 +++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 571 insertions(+) create mode 100644 usr.bin/write/term_chk.c create mode 100644 usr.bin/write/term_chk.h create mode 100644 usr.bin/write/write.1 create mode 100644 usr.bin/write/write.c (limited to 'usr.bin/write') diff --git a/usr.bin/write/term_chk.c b/usr.bin/write/term_chk.c new file mode 100644 index 0000000..d7d2cbe --- /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 0000000..aca4568 --- /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 0000000..28d614c --- /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 0000000..945e92f --- /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 +} -- cgit v1.2.3-60-g2f50