summaryrefslogtreecommitdiffstats
path: root/os/unix/unixd.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-07 02:04:06 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-07 02:04:06 +0000
commit5dff2d61cc1c27747ee398e04d8e02843aabb1f8 (patch)
treea67c336b406c8227bac912beb74a1ad3cdc55100 /os/unix/unixd.c
parentInitial commit. (diff)
downloadapache2-5dff2d61cc1c27747ee398e04d8e02843aabb1f8.tar.xz
apache2-5dff2d61cc1c27747ee398e04d8e02843aabb1f8.zip
Adding upstream version 2.4.38.upstream/2.4.38
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'os/unix/unixd.c')
-rw-r--r--os/unix/unixd.c733
1 files changed, 733 insertions, 0 deletions
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 */
+