/*
 *      Wrapper functions for 16bit uid back compatibility. All nicely tied
 *      together in the faint hope we can take the out in five years time.
 */

#include <linux/mm.h>
#include <linux/utsname.h>
#include <linux/mman.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/prctl.h>
#include <linux/capability.h>
#include <linux/init.h>
#include <linux/highuid.h>
#include <linux/security.h>
#include <linux/syscalls.h>

#include <asm/uaccess.h>

asmlinkage long sys_chown16(const char __user * filename, old_uid_t user, old_gid_t group)
{
        long ret = sys_chown(filename, low2highuid(user), low2highgid(group));
        /* avoid REGPARM breakage on x86: */
        asmlinkage_protect(3, ret, filename, user, group);
        return ret;
}

asmlinkage long sys_lchown16(const char __user * filename, old_uid_t user, old_gid_t group)
{
        long ret = sys_lchown(filename, low2highuid(user), low2highgid(group));
        /* avoid REGPARM breakage on x86: */
        asmlinkage_protect(3, ret, filename, user, group);
        return ret;
}

asmlinkage long sys_fchown16(unsigned int fd, old_uid_t user, old_gid_t group)
{
        long ret = sys_fchown(fd, low2highuid(user), low2highgid(group));
        /* avoid REGPARM breakage on x86: */
        asmlinkage_protect(3, ret, fd, user, group);
        return ret;
}

asmlinkage long sys_setregid16(old_gid_t rgid, old_gid_t egid)
{
        long ret = sys_setregid(low2highgid(rgid), low2highgid(egid));
        /* avoid REGPARM breakage on x86: */
        asmlinkage_protect(2, ret, rgid, egid);
        return ret;
}

asmlinkage long sys_setgid16(old_gid_t gid)
{
        long ret = sys_setgid(low2highgid(gid));
        /* avoid REGPARM breakage on x86: */
        asmlinkage_protect(1, ret, gid);
        return ret;
}

asmlinkage long sys_setreuid16(old_uid_t ruid, old_uid_t euid)
{
        long ret = sys_setreuid(low2highuid(ruid), low2highuid(euid));
        /* avoid REGPARM breakage on x86: */
        asmlinkage_protect(2, ret, ruid, euid);
        return ret;
}

asmlinkage long sys_setuid16(old_uid_t uid)
{
        long ret = sys_setuid(low2highuid(uid));
        /* avoid REGPARM breakage on x86: */
        asmlinkage_protect(1, ret, uid);
        return ret;
}

asmlinkage long sys_setresuid16(old_uid_t ruid, old_uid_t euid, old_uid_t suid)
{
        long ret = sys_setresuid(low2highuid(ruid), low2highuid(euid),
                                 low2highuid(suid));
        /* avoid REGPARM breakage on x86: */
        asmlinkage_protect(3, ret, ruid, euid, suid);
        return ret;
}

asmlinkage long sys_getresuid16(old_uid_t __user *ruid, old_uid_t __user *euid, old_uid_t __user *suid)
{
        int retval;

        if (!(retval = put_user(high2lowuid(current->uid), ruid)) &&
            !(retval = put_user(high2lowuid(current->euid), euid)))
                retval = put_user(high2lowuid(current->suid), suid);

        return retval;
}

asmlinkage long sys_setresgid16(old_gid_t rgid, old_gid_t egid, old_gid_t sgid)
{
        long ret = sys_setresgid(low2highgid(rgid), low2highgid(egid),
                                 low2highgid(sgid));
        /* avoid REGPARM breakage on x86: */
        asmlinkage_protect(3, ret, rgid, egid, sgid);
        return ret;
}

asmlinkage long sys_getresgid16(old_gid_t __user *rgid, old_gid_t __user *egid, old_gid_t __user *sgid)
{
        int retval;

        if (!(retval = put_user(high2lowgid(current->gid), rgid)) &&
            !(retval = put_user(high2lowgid(current->egid), egid)))
                retval = put_user(high2lowgid(current->sgid), sgid);

        return retval;
}

asmlinkage long sys_setfsuid16(old_uid_t uid)
{
        long ret = sys_setfsuid(low2highuid(uid));
        /* avoid REGPARM breakage on x86: */
        asmlinkage_protect(1, ret, uid);
        return ret;
}

asmlinkage long sys_setfsgid16(old_gid_t gid)
{
        long ret = sys_setfsgid(low2highgid(gid));
        /* avoid REGPARM breakage on x86: */
        asmlinkage_protect(1, ret, gid);
        return ret;
}

static int groups16_to_user(old_gid_t __user *grouplist,
    struct group_info *group_info)
{
        int i;
        old_gid_t group;

        for (i = 0; i < group_info->ngroups; i++) {
                group = high2lowgid(GROUP_AT(group_info, i));
                if (put_user(group, grouplist+i))
                        return -EFAULT;
        }

        return 0;
}

static int groups16_from_user(struct group_info *group_info,
    old_gid_t __user *grouplist)
{
        int i;
        old_gid_t group;

        for (i = 0; i < group_info->ngroups; i++) {
                if (get_user(group, grouplist+i))
                        return  -EFAULT;
                GROUP_AT(group_info, i) = low2highgid(group);
        }

        return 0;
}

asmlinkage long sys_getgroups16(int gidsetsize, old_gid_t __user *grouplist)
{
        int i = 0;

        if (gidsetsize < 0)
                return -EINVAL;

        get_group_info(current->group_info);
        i = current->group_info->ngroups;
        if (gidsetsize) {
                if (i > gidsetsize) {
                        i = -EINVAL;
                        goto out;
                }
                if (groups16_to_user(grouplist, current->group_info)) {
                        i = -EFAULT;
                        goto out;
                }
        }
out:
        put_group_info(current->group_info);
        return i;
}

asmlinkage long sys_setgroups16(int gidsetsize, old_gid_t __user *grouplist)
{
        struct group_info *group_info;
        int retval;

        if (!capable(CAP_SETGID))
                return -EPERM;
        if ((unsigned)gidsetsize > NGROUPS_MAX)
                return -EINVAL;

        group_info = groups_alloc(gidsetsize);
        if (!group_info)
                return -ENOMEM;
        retval = groups16_from_user(group_info, grouplist);
        if (retval) {
                put_group_info(group_info);
                return retval;
        }

        retval = set_current_groups(group_info);
        put_group_info(group_info);

        return retval;
}

asmlinkage long sys_getuid16(void)
{
        return high2lowuid(current->uid);
}

asmlinkage long sys_geteuid16(void)
{
        return high2lowuid(current->euid);
}

asmlinkage long sys_getgid16(void)
{
        return high2lowgid(current->gid);
}

asmlinkage long sys_getegid16(void)
{
        return high2lowgid(current->egid);
}