Adding upstream version 2.4.57.upstream/2.4.57upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

5 files changed, 939 insertions, 0 deletions

diff --git a/os/unix/Makefile.in b/os/unix/Makefile.in
new file mode 100644
index 0000000..eddb2c2
--- /dev/null
+++ b/os/unix/Makefile.in
@@ -0,0 +1,5 @@
+
+LTLIBRARY_NAME    = libos.la
+LTLIBRARY_SOURCES = unixd.c
+
+include $(top_srcdir)/build/ltlib.mk
diff --git a/os/unix/config.m4 b/os/unix/config.m4
new file mode 100644
index 0000000..dacbf6b
--- /dev/null
+++ b/os/unix/config.m4
@@ -0,0 +1,7 @@
+if test "$OS" = "unix" ; then
+    APACHE_TYPE_RLIM_T
+
+    AC_CHECK_HEADERS(sys/time.h sys/resource.h sys/sem.h sys/ipc.h)
+
+    AC_CHECK_FUNCS(setsid killpg)
+fi
diff --git a/os/unix/os.h b/os/unix/os.h
new file mode 100644
index 0000000..1494edd
--- /dev/null
+++ b/os/unix/os.h
@@ -0,0 +1,52 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * @file unix/os.h
+ * @brief This file in included in all Apache source code. It contains definitions
+ * of facilities available on _this_ operating system (HAVE_* macros),
+ * and prototypes of OS specific functions defined in os.c or os-inline.c
+ *
+ * @defgroup APACHE_OS_UNIX unix
+ * @ingroup  APACHE_OS
+ * @{
+ */
+
+#ifndef APACHE_OS_H
+#define APACHE_OS_H
+
+#include "apr.h"
+#include "ap_config.h"
+
+#ifndef PLATFORM
+#define PLATFORM "Unix"
+#endif
+
+/* On platforms where AP_NEED_SET_MUTEX_PERMS is defined, modules
+ * should call unixd_set_*_mutex_perms on mutexes created in the
+ * parent process. */
+#define AP_NEED_SET_MUTEX_PERMS 1
+
+/* Define command-line rewriting for this platform, handled by core.
+ */
+#define AP_PLATFORM_REWRITE_ARGS_HOOK ap_mpm_rewrite_args
+
+#ifdef _OSD_POSIX
+pid_t os_fork(const char *user);
+#endif
+
+#endif  /* !APACHE_OS_H */
+/** @} */
diff --git a/os/unix/unixd.c b/os/unix/unixd.c
new file mode 100644
index 0000000..0245720
--- /dev/null
+++ b/os/unix/unixd.c
@@ -0,0 +1,733 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "ap_config.h"
+#include "httpd.h"
+#include "http_config.h"
+#include "http_main.h"
+#include "http_core.h"
+#include "http_log.h"
+#include "unixd.h"
+#include "mpm_common.h"
+#include "os.h"
+#include "ap_mpm.h"
+#include "apr_thread_proc.h"
+#include "apr_signal.h"
+#include "apr_strings.h"
+#include "apr_portable.h"
+#ifdef HAVE_PWD_H
+#include <pwd.h>
+#endif
+#ifdef HAVE_SYS_RESOURCE_H
+#include <sys/resource.h>
+#endif
+/* XXX */
+#include <sys/stat.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_GRP_H
+#include <grp.h>
+#endif
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif
+#ifdef HAVE_SYS_SEM_H
+#include <sys/sem.h>
+#endif
+#ifdef HAVE_SYS_PRCTL_H
+#include <sys/prctl.h>
+#endif
+
+unixd_config_rec ap_unixd_config;
+
+APLOG_USE_MODULE(core);
+
+AP_DECLARE(void) ap_unixd_set_rlimit(cmd_parms *cmd, struct rlimit **plimit,
+                                     const char *arg,
+                                     const char * arg2, int type)
+{
+#if (defined(RLIMIT_CPU) || defined(RLIMIT_DATA) || defined(RLIMIT_VMEM) || defined(RLIMIT_NPROC) || defined(RLIMIT_AS)) && APR_HAVE_STRUCT_RLIMIT && APR_HAVE_GETRLIMIT
+    char *str;
+    struct rlimit *limit;
+    /* If your platform doesn't define rlim_t then typedef it in ap_config.h */
+    rlim_t cur = 0;
+    rlim_t max = 0;
+
+    *plimit = (struct rlimit *)apr_pcalloc(cmd->pool, sizeof(**plimit));
+    limit = *plimit;
+    if ((getrlimit(type, limit)) != 0)  {
+        *plimit = NULL;
+        ap_log_error(APLOG_MARK, APLOG_ERR, errno, cmd->server, APLOGNO(02172)
+                     "%s: getrlimit failed", cmd->cmd->name);
+        return;
+    }
+
+    if (*(str = ap_getword_conf(cmd->temp_pool, &arg)) != '\0') {
+        if (!strcasecmp(str, "max")) {
+            cur = limit->rlim_max;
+        }
+        else {
+            cur = atol(str);
+        }
+    }
+    else {
+        ap_log_error(APLOG_MARK, APLOG_ERR, 0, cmd->server, APLOGNO(02173)
+                     "Invalid parameters for %s", cmd->cmd->name);
+        return;
+    }
+
+    if (arg2 && (*(str = ap_getword_conf(cmd->temp_pool, &arg2)) != '\0')) {
+        max = atol(str);
+    }
+
+    /* if we aren't running as root, cannot increase max */
+    if (geteuid()) {
+        limit->rlim_cur = cur;
+        if (max && (max > limit->rlim_max)) {
+            ap_log_error(APLOG_MARK, APLOG_ERR, 0, cmd->server, APLOGNO(02174)
+                         "Must be uid 0 to raise maximum %s", cmd->cmd->name);
+        }
+        else if (max) {
+            limit->rlim_max = max;
+        }
+    }
+    else {
+        if (cur) {
+            limit->rlim_cur = cur;
+        }
+        if (max) {
+            limit->rlim_max = max;
+        }
+    }
+#else
+
+    ap_log_error(APLOG_MARK, APLOG_ERR, 0, cmd->server, APLOGNO(02175)
+                 "Platform does not support rlimit for %s", cmd->cmd->name);
+#endif
+}
+
+APR_HOOK_STRUCT(
+               APR_HOOK_LINK(get_suexec_identity)
+)
+
+AP_IMPLEMENT_HOOK_RUN_FIRST(ap_unix_identity_t *, get_suexec_identity,
+                         (const request_rec *r), (r), NULL)
+
+static apr_status_t ap_unix_create_privileged_process(
+                              apr_proc_t *newproc, const char *progname,
+                              const char * const *args,
+                              const char * const *env,
+                              apr_procattr_t *attr, ap_unix_identity_t *ugid,
+                              apr_pool_t *p)
+{
+    int i = 0;
+    const char **newargs;
+    char *newprogname;
+    char *execuser, *execgroup;
+    const char *argv0;
+
+    if (!ap_unixd_config.suexec_enabled) {
+        return apr_proc_create(newproc, progname, args, env, attr, p);
+    }
+
+    argv0 = ap_strrchr_c(progname, '/');
+    /* Allow suexec's "/" check to succeed */
+    if (argv0 != NULL) {
+        argv0++;
+    }
+    else {
+        argv0 = progname;
+    }
+
+
+    if (ugid->userdir) {
+        execuser = apr_psprintf(p, "~%ld", (long) ugid->uid);
+    }
+    else {
+        execuser = apr_psprintf(p, "%ld", (long) ugid->uid);
+    }
+    execgroup = apr_psprintf(p, "%ld", (long) ugid->gid);
+
+    if (!execuser || !execgroup) {
+        return APR_ENOMEM;
+    }
+
+    i = 0;
+    while (args[i])
+        i++;
+    /* allocate space for 4 new args, the input args, and a null terminator */
+    newargs = apr_palloc(p, sizeof(char *) * (i + 4));
+    newprogname = SUEXEC_BIN;
+    newargs[0] = SUEXEC_BIN;
+    newargs[1] = execuser;
+    newargs[2] = execgroup;
+    newargs[3] = apr_pstrdup(p, argv0);
+
+    /*
+    ** using a shell to execute suexec makes no sense thus
+    ** we force everything to be APR_PROGRAM, and never
+    ** APR_SHELLCMD
+    */
+    if (apr_procattr_cmdtype_set(attr, APR_PROGRAM) != APR_SUCCESS) {
+        return APR_EGENERAL;
+    }
+
+    i = 1;
+    do {
+        newargs[i + 3] = args[i];
+    } while (args[i++]);
+
+    return apr_proc_create(newproc, newprogname, newargs, env, attr, p);
+}
+
+AP_DECLARE(apr_status_t) ap_os_create_privileged_process(
+    const request_rec *r,
+    apr_proc_t *newproc, const char *progname,
+    const char * const *args,
+    const char * const *env,
+    apr_procattr_t *attr, apr_pool_t *p)
+{
+    ap_unix_identity_t *ugid = ap_run_get_suexec_identity(r);
+
+    if (ugid == NULL) {
+        return apr_proc_create(newproc, progname, args, env, attr, p);
+    }
+
+    return ap_unix_create_privileged_process(newproc, progname, args, env,
+                                              attr, ugid, p);
+}
+
+/* XXX move to APR and externalize (but implement differently :) ) */
+static apr_lockmech_e proc_mutex_mech(apr_proc_mutex_t *pmutex)
+{
+    const char *mechname = apr_proc_mutex_name(pmutex);
+
+    if (!strcmp(mechname, "sysvsem")) {
+        return APR_LOCK_SYSVSEM;
+    }
+    else if (!strcmp(mechname, "flock")) {
+        return APR_LOCK_FLOCK;
+    }
+    return APR_LOCK_DEFAULT;
+}
+
+AP_DECLARE(apr_status_t) ap_unixd_set_proc_mutex_perms(apr_proc_mutex_t *pmutex)
+{
+    if (!geteuid()) {
+        apr_lockmech_e mech = proc_mutex_mech(pmutex);
+
+        switch(mech) {
+#if APR_HAS_SYSVSEM_SERIALIZE
+        case APR_LOCK_SYSVSEM:
+        {
+            apr_os_proc_mutex_t ospmutex;
+#if !APR_HAVE_UNION_SEMUN
+            union semun {
+                long val;
+                struct semid_ds *buf;
+                unsigned short *array;
+            };
+#endif
+            union semun ick;
+            struct semid_ds buf = { { 0 } };
+
+            apr_os_proc_mutex_get(&ospmutex, pmutex);
+            buf.sem_perm.uid = ap_unixd_config.user_id;
+            buf.sem_perm.gid = ap_unixd_config.group_id;
+            buf.sem_perm.mode = 0600;
+            ick.buf = &buf;
+            if (semctl(ospmutex.crossproc, 0, IPC_SET, ick) < 0) {
+                return errno;
+            }
+        }
+        break;
+#endif
+#if APR_HAS_FLOCK_SERIALIZE
+        case APR_LOCK_FLOCK:
+        {
+            const char *lockfile = apr_proc_mutex_lockfile(pmutex);
+
+            if (lockfile) {
+                if (chown(lockfile, ap_unixd_config.user_id,
+                          -1 /* no gid change */) < 0) {
+                    return errno;
+                }
+            }
+        }
+        break;
+#endif
+        default:
+            /* do nothing */
+            break;
+        }
+    }
+    return APR_SUCCESS;
+}
+
+AP_DECLARE(apr_status_t) ap_unixd_set_global_mutex_perms(apr_global_mutex_t *gmutex)
+{
+#if !APR_PROC_MUTEX_IS_GLOBAL
+    apr_os_global_mutex_t osgmutex;
+    apr_os_global_mutex_get(&osgmutex, gmutex);
+    return ap_unixd_set_proc_mutex_perms(osgmutex.proc_mutex);
+#else  /* APR_PROC_MUTEX_IS_GLOBAL */
+    /* In this case, apr_proc_mutex_t and apr_global_mutex_t are the same. */
+    return ap_unixd_set_proc_mutex_perms(gmutex);
+#endif /* APR_PROC_MUTEX_IS_GLOBAL */
+}
+
+AP_DECLARE(apr_status_t) ap_unixd_accept(void **accepted, ap_listen_rec *lr,
+                                         apr_pool_t *ptrans)
+{
+    apr_socket_t *csd;
+    apr_status_t status;
+#ifdef _OSD_POSIX
+    int sockdes;
+#endif
+
+    *accepted = NULL;
+    status = apr_socket_accept(&csd, lr->sd, ptrans);
+    if (status == APR_SUCCESS) {
+        *accepted = csd;
+#ifdef _OSD_POSIX
+        apr_os_sock_get(&sockdes, csd);
+        if (sockdes >= FD_SETSIZE) {
+            ap_log_error(APLOG_MARK, APLOG_WARNING, 0, ap_server_conf, APLOGNO(02176)
+                         "new file descriptor %d is too large; you probably need "
+                         "to rebuild Apache with a larger FD_SETSIZE "
+                         "(currently %d)",
+                         sockdes, FD_SETSIZE);
+            apr_socket_close(csd);
+            return APR_EINTR;
+        }
+#endif
+        return APR_SUCCESS;
+    }
+
+    if (APR_STATUS_IS_EINTR(status)) {
+        return status;
+    }
+    /* Our old behaviour here was to continue after accept()
+     * errors.  But this leads us into lots of troubles
+     * because most of the errors are quite fatal.  For
+     * example, EMFILE can be caused by slow descriptor
+     * leaks (say in a 3rd party module, or libc).  It's
+     * foolish for us to continue after an EMFILE.  We also
+     * seem to tickle kernel bugs on some platforms which
+     * lead to never-ending loops here.  So it seems best
+     * to just exit in most cases.
+     */
+    switch (status) {
+#if defined(HPUX11) && defined(ENOBUFS)
+        /* On HPUX 11.x, the 'ENOBUFS, No buffer space available'
+         * error occurs because the accept() cannot complete.
+         * You will not see ENOBUFS with 10.20 because the kernel
+         * hides any occurrence from being returned to user space.
+         * ENOBUFS with 11.x's TCP/IP stack is possible, and could
+         * occur intermittently. As a work-around, we are going to
+         * ignore ENOBUFS.
+         */
+        case ENOBUFS:
+#endif
+
+#ifdef EPROTO
+        /* EPROTO on certain older kernels really means
+         * ECONNABORTED, so we need to ignore it for them.
+         * See discussion in new-httpd archives nh.9701
+         * search for EPROTO.
+         *
+         * Also see nh.9603, search for EPROTO:
+         * There is potentially a bug in Solaris 2.x x<6,
+         * and other boxes that implement tcp sockets in
+         * userland (i.e. on top of STREAMS).  On these
+         * systems, EPROTO can actually result in a fatal
+         * loop.  See PR#981 for example.  It's hard to
+         * handle both uses of EPROTO.
+         */
+        case EPROTO:
+#endif
+#ifdef ECONNABORTED
+        case ECONNABORTED:
+#endif
+        /* Linux generates the rest of these, other tcp
+         * stacks (i.e. bsd) tend to hide them behind
+         * getsockopt() interfaces.  They occur when
+         * the net goes sour or the client disconnects
+         * after the three-way handshake has been done
+         * in the kernel but before userland has picked
+         * up the socket.
+         */
+#ifdef ECONNRESET
+        case ECONNRESET:
+#endif
+#ifdef ETIMEDOUT
+        case ETIMEDOUT:
+#endif
+#ifdef EHOSTUNREACH
+        case EHOSTUNREACH:
+#endif
+#ifdef ENETUNREACH
+        case ENETUNREACH:
+#endif
+        /* EAGAIN/EWOULDBLOCK can be returned on BSD-derived
+         * TCP stacks when the connection is aborted before
+         * we call connect, but only because our listener
+         * sockets are non-blocking (AP_NONBLOCK_WHEN_MULTI_LISTEN)
+         */
+#ifdef EAGAIN
+        case EAGAIN:
+#endif
+#ifdef EWOULDBLOCK
+#if !defined(EAGAIN) || EAGAIN != EWOULDBLOCK
+        case EWOULDBLOCK:
+#endif
+#endif
+            break;
+#ifdef ENETDOWN
+        case ENETDOWN:
+            /*
+             * When the network layer has been shut down, there
+             * is not much use in simply exiting: the parent
+             * would simply re-create us (and we'd fail again).
+             * Use the CHILDFATAL code to tear the server down.
+             * @@@ Martin's idea for possible improvement:
+             * A different approach would be to define
+             * a new APEXIT_NETDOWN exit code, the reception
+             * of which would make the parent shutdown all
+             * children, then idle-loop until it detected that
+             * the network is up again, and restart the children.
+             * Ben Hyde noted that temporary ENETDOWN situations
+             * occur in mobile IP.
+             */
+            ap_log_error(APLOG_MARK, APLOG_EMERG, status, ap_server_conf, APLOGNO(02177)
+                         "apr_socket_accept: giving up.");
+            return APR_EGENERAL;
+#endif /*ENETDOWN*/
+
+        default:
+            /* If the socket has been closed in ap_close_listeners()
+             * by the restart/stop action, we may get EBADF.
+             * Do not print an error in this case.
+             */
+            if (!lr->active) {
+                ap_log_error(APLOG_MARK, APLOG_DEBUG, status, ap_server_conf, APLOGNO(02178)
+                             "apr_socket_accept failed for inactive listener");
+                return status;
+            }
+            ap_log_error(APLOG_MARK, APLOG_ERR, status, ap_server_conf, APLOGNO(02179)
+                         "apr_socket_accept: (client socket)");
+            return APR_EGENERAL;
+    }
+    return status;
+}
+
+
+/* Unixes MPMs' */
+
+static ap_unixd_mpm_retained_data *retained_data = NULL;
+static apr_status_t retained_data_cleanup(void *unused)
+{
+    (void)unused;
+    retained_data = NULL;
+    return APR_SUCCESS;
+}
+
+AP_DECLARE(ap_unixd_mpm_retained_data *) ap_unixd_mpm_get_retained_data()
+{
+    if (!retained_data) {
+        retained_data = ap_retained_data_create("ap_unixd_mpm_retained_data",
+                                                sizeof(*retained_data));
+        apr_pool_pre_cleanup_register(ap_pglobal, NULL, retained_data_cleanup);
+        retained_data->mpm_state = AP_MPMQ_STARTING;
+    }
+    return retained_data;
+}
+
+static void sig_term(int sig)
+{
+    if (!retained_data) {
+        /* Main process (ap_pglobal) is dying */
+        return;
+    }
+    retained_data->mpm_state = AP_MPMQ_STOPPING;
+    if (retained_data->shutdown_pending
+            && (retained_data->is_ungraceful
+                || sig == AP_SIG_GRACEFUL_STOP)) {
+        /* Already handled */
+        return;
+    }
+
+    retained_data->shutdown_pending = 1;
+    if (sig != AP_SIG_GRACEFUL_STOP) {
+        retained_data->is_ungraceful = 1;
+    }
+}
+
+static void sig_restart(int sig)
+{
+    if (!retained_data) {
+        /* Main process (ap_pglobal) is dying */
+        return;
+    }
+    retained_data->mpm_state = AP_MPMQ_STOPPING;
+    if (retained_data->restart_pending
+            && (retained_data->is_ungraceful
+                || sig == AP_SIG_GRACEFUL)) {
+        /* Already handled */
+        return;
+    }
+
+    retained_data->restart_pending = 1;
+    if (sig != AP_SIG_GRACEFUL) {
+        retained_data->is_ungraceful = 1;
+    }
+}
+
+static apr_status_t unset_signals(void *unused)
+{
+    if (!retained_data) {
+        /* Main process (ap_pglobal) is dying */
+        return APR_SUCCESS;
+    }
+    retained_data->shutdown_pending = retained_data->restart_pending = 0;
+    retained_data->was_graceful = !retained_data->is_ungraceful;
+    retained_data->is_ungraceful = 0;
+
+    return APR_SUCCESS;
+}
+
+static void ap_terminate(void)
+{
+    ap_main_state = AP_SQ_MS_EXITING;
+    apr_pool_destroy(ap_pglobal);
+    apr_terminate();
+}
+
+AP_DECLARE(void) ap_unixd_mpm_set_signals(apr_pool_t *pconf, int one_process)
+{
+#ifndef NO_USE_SIGACTION
+    struct sigaction sa;
+#endif
+
+    if (!one_process) {
+        ap_fatal_signal_setup(ap_server_conf, pconf);
+    }
+    else if (!ap_retained_data_get("ap_unixd_mpm_one_process_cleanup")) {
+        /* In one process mode (debug), httpd will exit immediately when asked
+         * to (SIGTERM/SIGINT) and never restart. We still want the cleanups to
+         * run though (such that e.g. temporary files/IPCs don't leak on the
+         * system), so the first time around we use atexit() to cleanup after
+         * ourselves.
+         */
+        ap_retained_data_create("ap_unixd_mpm_one_process_cleanup", 1);
+        atexit(ap_terminate);
+    }
+
+    /* Signals' handlers depend on retained data */
+    (void)ap_unixd_mpm_get_retained_data();
+
+#ifndef NO_USE_SIGACTION
+    memset(&sa, 0, sizeof sa);
+    sigemptyset(&sa.sa_mask);
+
+#ifdef SIGPIPE
+    sa.sa_handler = SIG_IGN;
+    if (sigaction(SIGPIPE, &sa, NULL) < 0)
+        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00269)
+                     "sigaction(SIGPIPE)");
+#endif
+#ifdef SIGXCPU
+    sa.sa_handler = SIG_DFL;
+    if (sigaction(SIGXCPU, &sa, NULL) < 0)
+        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00267)
+                     "sigaction(SIGXCPU)");
+#endif
+#ifdef SIGXFSZ
+    /* For systems following the LFS standard, ignoring SIGXFSZ allows
+     * a write() beyond the 2GB limit to fail gracefully with E2BIG
+     * rather than terminate the process. */
+    sa.sa_handler = SIG_IGN;
+    if (sigaction(SIGXFSZ, &sa, NULL) < 0)
+        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00268)
+                     "sigaction(SIGXFSZ)");
+#endif
+
+    sa.sa_handler = sig_term;
+    if (sigaction(SIGTERM, &sa, NULL) < 0)
+        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00264)
+                     "sigaction(SIGTERM)");
+#ifdef SIGINT
+    if (sigaction(SIGINT, &sa, NULL) < 0)
+        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00266)
+                     "sigaction(SIGINT)");
+#endif
+#ifdef AP_SIG_GRACEFUL_STOP
+    if (sigaction(AP_SIG_GRACEFUL_STOP, &sa, NULL) < 0)
+        ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00265)
+                     "sigaction(" AP_SIG_GRACEFUL_STOP_STRING ")");
+#endif
+
+    /* Don't catch restart signals in ONE_PROCESS mode :) */
+    if (!one_process) {
+        sa.sa_handler = sig_restart;
+        if (sigaction(SIGHUP, &sa, NULL) < 0)
+            ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00270)
+                         "sigaction(SIGHUP)");
+        if (sigaction(AP_SIG_GRACEFUL, &sa, NULL) < 0)
+            ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, APLOGNO(00271)
+                         "sigaction(" AP_SIG_GRACEFUL_STRING ")");
+    }
+
+#else  /* NO_USE_SIGACTION */
+
+#ifdef SIGPIPE
+    apr_signal(SIGPIPE, SIG_IGN);
+#endif /* SIGPIPE */
+#ifdef SIGXCPU
+    apr_signal(SIGXCPU, SIG_DFL);
+#endif /* SIGXCPU */
+#ifdef SIGXFSZ
+    apr_signal(SIGXFSZ, SIG_IGN);
+#endif /* SIGXFSZ */
+
+    apr_signal(SIGTERM, sig_term);
+#ifdef AP_SIG_GRACEFUL_STOP
+    apr_signal(AP_SIG_GRACEFUL_STOP, sig_term);
+#endif /* AP_SIG_GRACEFUL_STOP */
+
+    if (!one_process) {
+        /* Don't restart in ONE_PROCESS mode :) */
+#ifdef SIGHUP
+        apr_signal(SIGHUP, sig_restart);
+#endif /* SIGHUP */
+#ifdef AP_SIG_GRACEFUL
+        apr_signal(AP_SIG_GRACEFUL, sig_restart);
+#endif /* AP_SIG_GRACEFUL */
+    }
+
+#endif /* NO_USE_SIGACTION */
+
+    apr_pool_cleanup_register(pconf, NULL, unset_signals,
+                              apr_pool_cleanup_null);
+}
+
+
+#ifdef _OSD_POSIX
+
+#include "apr_lib.h"
+
+#define USER_LEN 8
+
+typedef enum
+{
+    bs2_unknown,     /* not initialized yet. */
+    bs2_noFORK,      /* no fork() because -X flag was specified */
+    bs2_FORK,        /* only fork() because uid != 0 */
+    bs2_UFORK        /* Normally, ufork() is used to switch identities. */
+} bs2_ForkType;
+
+static bs2_ForkType forktype = bs2_unknown;
+
+/* Determine the method for forking off a child in such a way as to
+ * set both the POSIX and BS2000 user id's to the unprivileged user.
+ */
+static bs2_ForkType os_forktype(int one_process)
+{
+    /* have we checked the OS version before? If yes return the previous
+     * result - the OS release isn't going to change suddenly!
+     */
+    if (forktype == bs2_unknown) {
+        /* not initialized yet */
+
+        /* No fork if the one_process option was set */
+        if (one_process) {
+            forktype = bs2_noFORK;
+        }
+        /* If the user is unprivileged, use the normal fork() only. */
+        else if (getuid() != 0) {
+            forktype = bs2_FORK;
+        }
+        else
+            forktype = bs2_UFORK;
+    }
+    return forktype;
+}
+
+
+
+/* This routine complements the setuid() call: it causes the BS2000 job
+ * environment to be switched to the target user's user id.
+ * That is important if CGI scripts try to execute native BS2000 commands.
+ */
+int os_init_job_environment(server_rec *server, const char *user_name, int one_process)
+{
+    bs2_ForkType            type = os_forktype(one_process);
+
+    /* We can be sure that no change to uid==0 is possible because of
+     * the checks in http_core.c:set_user()
+     */
+
+    if (one_process) {
+
+        type = forktype = bs2_noFORK;
+
+        ap_log_error(APLOG_MARK, APLOG_ERR, 0, server, APLOGNO(02180)
+                     "The debug mode of Apache should only "
+                     "be started by an unprivileged user!");
+        return 0;
+    }
+
+    return 0;
+}
+
+/* BS2000 requires a "special" version of fork() before a setuid() call */
+pid_t os_fork(const char *user)
+{
+    pid_t pid;
+    char  username[USER_LEN+1];
+
+    switch (os_forktype(0)) {
+
+      case bs2_FORK:
+        pid = fork();
+        break;
+
+      case bs2_UFORK:
+        apr_cpystrn(username, user, sizeof username);
+
+        /* Make user name all upper case - for some versions of ufork() */
+        ap_str_toupper(username);
+
+        pid = ufork(username);
+        if (pid == -1 && errno == EPERM) {
+            ap_log_error(APLOG_MARK, APLOG_EMERG, errno, ap_server_conf,
+                         APLOGNO(02181) "ufork: Possible mis-configuration "
+                         "for user %s - Aborting.", user);
+            exit(1);
+        }
+        break;
+
+      default:
+        pid = 0;
+        break;
+    }
+
+    return pid;
+}
+
+#endif /* _OSD_POSIX */
+
diff --git a/os/unix/unixd.h b/os/unix/unixd.h
new file mode 100644
index 0000000..ed977c6
--- /dev/null
+++ b/os/unix/unixd.h
@@ -0,0 +1,142 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * @file  unixd.h
+ * @brief common stuff that unix MPMs will want
+ *
+ * @addtogroup APACHE_OS_UNIX
+ * @{
+ */
+
+#ifndef UNIXD_H
+#define UNIXD_H
+
+#include "httpd.h"
+#include "http_config.h"
+#include "scoreboard.h"
+#include "ap_listen.h"
+#ifdef HAVE_SYS_TIME_H
+#include <sys/time.h>
+#endif
+#ifdef HAVE_SYS_RESOURCE_H
+#include <sys/resource.h>
+#endif
+#include "apr_hooks.h"
+#include "apr_thread_proc.h"
+#include "apr_proc_mutex.h"
+#include "apr_global_mutex.h"
+
+#include <pwd.h>
+#include <grp.h>
+#if APR_HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_IPC_H
+#include <sys/ipc.h>
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+    uid_t uid;
+    gid_t gid;
+    int userdir;
+} ap_unix_identity_t;
+
+AP_DECLARE_HOOK(ap_unix_identity_t *, get_suexec_identity,(const request_rec *r))
+
+
+/* Default user name and group name. These may be specified as numbers by
+ * placing a # before a number */
+
+#ifndef DEFAULT_USER
+#define DEFAULT_USER "#-1"
+#endif
+#ifndef DEFAULT_GROUP
+#define DEFAULT_GROUP "#-1"
+#endif
+
+typedef struct {
+    const char *user_name;
+    const char *group_name;
+    uid_t user_id;
+    gid_t group_id;
+    int suexec_enabled;
+    const char *chroot_dir;
+    const char *suexec_disabled_reason; /* suitable msg if !suexec_enabled */
+} unixd_config_rec;
+AP_DECLARE_DATA extern unixd_config_rec ap_unixd_config;
+
+#if defined(RLIMIT_CPU) || defined(RLIMIT_DATA) || defined(RLIMIT_VMEM) || defined(RLIMIT_NPROC) || defined(RLIMIT_AS)
+AP_DECLARE(void) ap_unixd_set_rlimit(cmd_parms *cmd, struct rlimit **plimit,
+                                     const char *arg,
+                                     const char * arg2, int type);
+#endif
+
+/**
+ * One of the functions to set mutex permissions should be called in
+ * the parent process on platforms that switch identity when the
+ * server is started as root.
+ * If the child init logic is performed before switching identity
+ * (e.g., MPM setup for an accept mutex), it should only be called
+ * for SysV semaphores.  Otherwise, it is safe to call it for all
+ * mutex types.
+ */
+AP_DECLARE(apr_status_t) ap_unixd_set_proc_mutex_perms(apr_proc_mutex_t *pmutex);
+AP_DECLARE(apr_status_t) ap_unixd_set_global_mutex_perms(apr_global_mutex_t *gmutex);
+AP_DECLARE(apr_status_t) ap_unixd_accept(void **accepted, ap_listen_rec *lr, apr_pool_t *ptrans);
+
+#ifdef HAVE_KILLPG
+#define ap_unixd_killpg(x, y)   (killpg ((x), (y)))
+#define ap_os_killpg(x, y)      (killpg ((x), (y)))
+#else /* HAVE_KILLPG */
+#define ap_unixd_killpg(x, y)   (kill (-(x), (y)))
+#define ap_os_killpg(x, y)      (kill (-(x), (y)))
+#endif /* HAVE_KILLPG */
+
+typedef struct {
+    void            *baton;  /* MPM's */
+
+    /* volatile because they're updated from signals' handlers */
+    int volatile    mpm_state;
+    int volatile    shutdown_pending;
+    int volatile    restart_pending;
+    int volatile    is_ungraceful;
+
+    ap_generation_t my_generation;
+    int             module_loads;
+    int             was_graceful;
+
+    /*
+     * Current number of listeners buckets and maximum reached across
+     * restarts (to size retained data according to dynamic num_buckets,
+     * eg. idle_spawn_rate).
+     */
+    int num_buckets, max_buckets;
+} ap_unixd_mpm_retained_data;
+
+AP_DECLARE(ap_unixd_mpm_retained_data *) ap_unixd_mpm_get_retained_data(void);
+AP_DECLARE(void) ap_unixd_mpm_set_signals(apr_pool_t *pconf, int once_process);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+/** @} */