0de3c55b42
login: sanitize stdio descriptors (we are suid, need to be careful!) shrink login and set_environment by ~100 bytes.
77 lines
3.0 KiB
C
77 lines
3.0 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* Copyright 1989 - 1991, Julianne Frances Haugh <jockgrrl@austin.rr.com>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of Julianne F. Haugh nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY JULIE HAUGH AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL JULIE HAUGH OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include "libbb.h"
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/* util-linux manpage says /sbin:/bin:/usr/sbin:/usr/bin,
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* but I want to save a few bytes here */
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static const char DEFAULT_ROOT_LOGIN_PATH[] = "/sbin:/usr/sbin:/bin:/usr/bin";
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#define DEFAULT_LOGIN_PATH (DEFAULT_ROOT_LOGIN_PATH + sizeof("/sbin:/usr/sbin"))
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void setup_environment(const char *shell, int loginshell, int changeenv, const struct passwd *pw)
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{
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if (loginshell) {
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const char *term;
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/* Change the current working directory to be the home directory
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* of the user. It is a fatal error for this process to be unable
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* to change to that directory. There is no "default" home
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* directory.
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* Some systems default to HOME=/
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*/
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if (chdir(pw->pw_dir)) {
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xchdir("/");
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fputs("warning: cannot change to home directory\n", stderr);
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}
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/* Leave TERM unchanged. Set HOME, SHELL, USER, LOGNAME, PATH.
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Unset all other environment variables. */
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term = getenv("TERM");
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clearenv();
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if (term)
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xsetenv("TERM", term);
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xsetenv("HOME", pw->pw_dir);
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xsetenv("SHELL", shell);
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xsetenv("USER", pw->pw_name);
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xsetenv("LOGNAME", pw->pw_name);
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xsetenv("PATH", (pw->pw_uid ? DEFAULT_LOGIN_PATH : DEFAULT_ROOT_LOGIN_PATH));
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}
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else if (changeenv) {
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/* Set HOME, SHELL, and if not becoming a super-user,
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USER and LOGNAME. */
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xsetenv("HOME", pw->pw_dir);
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xsetenv("SHELL", shell);
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if (pw->pw_uid) {
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xsetenv("USER", pw->pw_name);
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xsetenv("LOGNAME", pw->pw_name);
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}
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}
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}
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