# Copyright (C) Igor Sysoev
# Copyright (C) NGINX, Inc.

# Linux clone syscall.

NXT_ISOLATION=NO
NXT_HAVE_LINUX_NS=NO
NXT_HAVE_CLONE_NEWUSER=NO
NXT_HAVE_MOUNT=NO
NXT_HAVE_UNMOUNT=NO
NXT_HAVE_ROOTFS=NO

nsflags="USER NS PID NET UTS CGROUP"

nxt_feature="Linux unshare()"
nxt_feature_name=NXT_HAVE_LINUX_NS
nxt_feature_run=no
nxt_feature_incs=
nxt_feature_libs=
nxt_feature_test="#define _GNU_SOURCE
                  #include <sched.h>

                  int main(void) {
                      return unshare(0);
                  }"
. auto/feature

if [ $nxt_found = yes ]; then
    NXT_HAVE_LINUX_NS=YES

    # Test all isolation flags
    for flag in $nsflags; do
        nxt_feature="CLONE_NEW${flag}"
        nxt_feature_name=NXT_HAVE_CLONE_NEW${flag}
        nxt_feature_run=no
        nxt_feature_incs=
        nxt_feature_libs=
        nxt_feature_test="#define _GNU_SOURCE
                          #include <sys/wait.h>
                          #include <sys/syscall.h>
                          #include <sched.h>

                          int main(void) {
                              return CLONE_NEW$flag;
                         }"
        . auto/feature

        if [ $nxt_found = yes ]; then
            if [ $flag = "USER" ]; then
                NXT_HAVE_CLONE_NEWUSER=YES
            fi

            if [ "$NXT_ISOLATION" = "NO" ]; then
                NXT_ISOLATION=$flag
            else
                NXT_ISOLATION="$NXT_ISOLATION $flag"
            fi
        fi
    done
fi


nxt_feature="Linux pivot_root()"
nxt_feature_name=NXT_HAVE_LINUX_PIVOT_ROOT
nxt_feature_run=no
nxt_feature_incs=
nxt_feature_libs=
nxt_feature_test="#include <sys/syscall.h>
                  #if !defined(__linux__)
                  # error
                  #endif

                  int main(void) {
                      return SYS_pivot_root;
                  }"
. auto/feature


nxt_feature="<mntent.h>"
nxt_feature_name=NXT_HAVE_MNTENT_H
nxt_feature_run=no
nxt_feature_incs=
nxt_feature_libs=
nxt_feature_test="#include <mntent.h>

                  int main(void) {
                      return 0;
                  }"
. auto/feature


nxt_feature="prctl(PR_SET_NO_NEW_PRIVS)"
nxt_feature_name=NXT_HAVE_PR_SET_NO_NEW_PRIVS
nxt_feature_run=no
nxt_feature_incs=
nxt_feature_libs=
nxt_feature_test="#include <sys/prctl.h>

                  int main(void) {
                      return PR_SET_NO_NEW_PRIVS;
                  }"
. auto/feature


nxt_feature="prctl(PR_SET_CHILD_SUBREAPER)"
nxt_feature_name=NXT_HAVE_PR_SET_CHILD_SUBREAPER
nxt_feature_run=no
nxt_feature_incs=
nxt_feature_libs=
nxt_feature_test="#include <sys/prctl.h>

                  int main(void) {
                      return PR_SET_CHILD_SUBREAPER;
                  }"
. auto/feature


nxt_feature="Linux mount()"
nxt_feature_name=NXT_HAVE_LINUX_MOUNT
nxt_feature_run=no
nxt_feature_incs=
nxt_feature_libs=
nxt_feature_test="#include <sys/mount.h>

                  int main(void) {
                      return mount(\"/\", \"/\", \"bind\",
                                   MS_BIND | MS_REC, \"\");
                  }"
. auto/feature

if [ $nxt_found = yes ]; then
    NXT_HAVE_MOUNT=YES
fi


if [ $nxt_found = no ]; then
    nxt_feature="FreeBSD nmount()"
    nxt_feature_name=NXT_HAVE_FREEBSD_NMOUNT
    nxt_feature_run=no
    nxt_feature_incs=
    nxt_feature_libs=
    nxt_feature_test="#include <sys/mount.h>

                    int main(void) {
                        return nmount((void *)0, 0, 0);
                    }"
    . auto/feature

    if [ $nxt_found = yes ]; then
        NXT_HAVE_MOUNT=YES
    fi
fi


nxt_feature="Linux umount2()"
nxt_feature_name=NXT_HAVE_LINUX_UMOUNT2
nxt_feature_run=no
nxt_feature_incs=
nxt_feature_libs=
nxt_feature_test="#include <sys/mount.h>

                  int main(void) {
                      return umount2((void *)0, 0);
                  }"
. auto/feature

if [ $nxt_found = yes ]; then
    NXT_HAVE_UNMOUNT=YES
fi

if [ $nxt_found = no ]; then
    nxt_feature="unmount()"
    nxt_feature_name=NXT_HAVE_UNMOUNT
    nxt_feature_run=no
    nxt_feature_incs=
    nxt_feature_libs=
    nxt_feature_test="#include <sys/mount.h>

                    int main(void) {
                        return unmount((void *)0, 0);
                    }"
    . auto/feature

    if [ $nxt_found = yes ]; then
        NXT_HAVE_UNMOUNT=YES
    fi
fi

if [ $NXT_HAVE_MOUNT = YES -a $NXT_HAVE_UNMOUNT = YES ]; then
    NXT_HAVE_ROOTFS=YES

    cat << END >> $NXT_AUTO_CONFIG_H

#ifndef NXT_HAVE_ISOLATION_ROOTFS
#define NXT_HAVE_ISOLATION_ROOTFS  1
#endif

END

fi