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/* $Id: platform.c,v 1.22 2014/07/18 04:11:26 djm Exp $ */
/*
* Copyright (c) 2006 Darren Tucker. All rights reserved.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "includes.h"
#include <sys/types.h>
#if defined(HAVE_SYS_PRCTL_H)
#include <sys/prctl.h> /* For prctl() and PR_SET_DUMPABLE */
#endif
#include <stdarg.h>
#include <unistd.h>
#include "log.h"
#include "buffer.h"
#include "misc.h"
#include "servconf.h"
#include "key.h"
#include "hostfile.h"
#include "auth.h"
#include "auth-pam.h"
#include "platform.h"
#include "openbsd-compat/openbsd-compat.h"
extern int use_privsep;
extern ServerOptions options;
void
platform_pre_listen(void)
{
#ifdef LINUX_OOM_ADJUST
/* Adjust out-of-memory killer so listening process is not killed */
oom_adjust_setup();
#endif
}
void
platform_pre_fork(void)
{
#ifdef USE_SOLARIS_PROCESS_CONTRACTS
solaris_contract_pre_fork();
#endif
}
void
platform_pre_restart(void)
{
#ifdef LINUX_OOM_ADJUST
oom_adjust_restore();
#endif
}
void
platform_post_fork_parent(pid_t child_pid)
{
#ifdef USE_SOLARIS_PROCESS_CONTRACTS
solaris_contract_post_fork_parent(child_pid);
#endif
}
void
platform_post_fork_child(void)
{
#ifdef USE_SOLARIS_PROCESS_CONTRACTS
solaris_contract_post_fork_child();
#endif
#ifdef LINUX_OOM_ADJUST
oom_adjust_restore();
#endif
}
/* return 1 if we are running with privilege to swap UIDs, 0 otherwise */
int
platform_privileged_uidswap(void)
{
#ifdef HAVE_CYGWIN
/* uid 0 is not special on Cygwin so always try */
return 1;
#else
return (getuid() == 0 || geteuid() == 0);
#endif
}
/*
* This gets called before switching UIDs, and is called even when sshd is
* not running as root.
*/
void
platform_setusercontext(struct passwd *pw)
{
#ifdef WITH_SELINUX
/* Cache selinux status for later use */
(void)ssh_selinux_enabled();
#endif
#ifdef USE_SOLARIS_PROJECTS
/*
* If solaris projects were detected, set the default now, unless
* we are using PAM in which case it is the responsibility of the
* PAM stack.
*/
if (!options.use_pam && (getuid() == 0 || geteuid() == 0))
solaris_set_default_project(pw);
#endif
#if defined(HAVE_LOGIN_CAP) && defined (__bsdi__)
if (getuid() == 0 || geteuid() == 0)
setpgid(0, 0);
# endif
#if defined(HAVE_LOGIN_CAP) && defined(USE_PAM)
/*
* If we have both LOGIN_CAP and PAM, we want to establish creds
* before calling setusercontext (in session.c:do_setusercontext).
*/
if (getuid() == 0 || geteuid() == 0) {
if (options.use_pam) {
do_pam_setcred(use_privsep);
}
}
# endif /* USE_PAM */
#if !defined(HAVE_LOGIN_CAP) && defined(HAVE_GETLUID) && defined(HAVE_SETLUID)
if (getuid() == 0 || geteuid() == 0) {
/* Sets login uid for accounting */
if (getluid() == -1 && setluid(pw->pw_uid) == -1)
error("setluid: %s", strerror(errno));
}
#endif
}
/*
* This gets called after we've established the user's groups, and is only
* called if sshd is running as root.
*/
void
platform_setusercontext_post_groups(struct passwd *pw)
{
#if !defined(HAVE_LOGIN_CAP) && defined(USE_PAM)
/*
* PAM credentials may take the form of supplementary groups.
* These will have been wiped by the above initgroups() call.
* Reestablish them here.
*/
if (options.use_pam) {
do_pam_setcred(use_privsep);
}
#endif /* USE_PAM */
#if !defined(HAVE_LOGIN_CAP) && (defined(WITH_IRIX_PROJECT) || \
defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY))
irix_setusercontext(pw);
#endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
#ifdef _AIX
aix_usrinfo(pw);
#endif /* _AIX */
#ifdef HAVE_SETPCRED
/*
* If we have a chroot directory, we set all creds except real
* uid which we will need for chroot. If we don't have a
* chroot directory, we don't override anything.
*/
{
char **creds = NULL, *chroot_creds[] =
{ "REAL_USER=root", NULL };
if (options.chroot_directory != NULL &&
strcasecmp(options.chroot_directory, "none") != 0)
creds = chroot_creds;
if (setpcred(pw->pw_name, creds) == -1)
fatal("Failed to set process credentials");
}
#endif /* HAVE_SETPCRED */
#ifdef WITH_SELINUX
ssh_selinux_setup_exec_context(pw->pw_name);
#endif
}
char *
platform_krb5_get_principal_name(const char *pw_name)
{
#ifdef USE_AIX_KRB_NAME
return aix_krb5_get_principal_name(pw_name);
#else
return NULL;
#endif
}
/*
* return 1 if the specified uid is a uid that may own a system directory
* otherwise 0.
*/
int
platform_sys_dir_uid(uid_t uid)
{
if (uid == 0)
return 1;
#ifdef PLATFORM_SYS_DIR_UID
if (uid == PLATFORM_SYS_DIR_UID)
return 1;
#endif
return 0;
}
void
platform_disable_tracing(int strict)
{
#if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
/* Disable ptrace on Linux without sgid bit */
if (prctl(PR_SET_DUMPABLE, 0) != 0 && strict)
fatal("unable to make the process undumpable");
#endif
}
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