// SPDX-License-Identifier: GPL-2.0
/*
 * sys_ipc() is the old de-multiplexer for the SysV IPC calls.
 *
 * This is really horribly ugly, and new architectures should just wire up
 * the individual syscalls instead.
 */
#include <linux/unistd.h>
#include <linux/syscalls.h>
#include <linux/security.h>
#include <linux/ipc_namespace.h>
#include "util.h"

#ifdef __ARCH_WANT_SYS_IPC
#include <linux/errno.h>
#include <linux/ipc.h>
#include <linux/shm.h>
#include <linux/uaccess.h>

int ksys_ipc(unsigned int call, int first, unsigned long second,
        unsigned long third, void __user * ptr, long fifth)
{
        int version, ret;

        version = call >> 16; /* hack for backward compatibility */
        call &= 0xffff;

        switch (call) {
        case SEMOP:
                return ksys_semtimedop(first, (struct sembuf __user *)ptr,
                                       second, NULL);
        case SEMTIMEDOP:
                if (IS_ENABLED(CONFIG_64BIT))
                        return ksys_semtimedop(first, ptr, second,
                                (const struct __kernel_timespec __user *)fifth);
                else if (IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))
                        return compat_ksys_semtimedop(first, ptr, second,
                                (const struct old_timespec32 __user *)fifth);
                else
                        return -ENOSYS;

        case SEMGET:
                return ksys_semget(first, second, third);
        case SEMCTL: {
                unsigned long arg;
                if (!ptr)
                        return -EINVAL;
                if (get_user(arg, (unsigned long __user *) ptr))
                        return -EFAULT;
                return ksys_old_semctl(first, second, third, arg);
        }

        case MSGSND:
                return ksys_msgsnd(first, (struct msgbuf __user *) ptr,
                                  second, third);
        case MSGRCV:
                switch (version) {
                case 0: {
                        struct ipc_kludge tmp;
                        if (!ptr)
                                return -EINVAL;

                        if (copy_from_user(&tmp,
                                           (struct ipc_kludge __user *) ptr,
                                           sizeof(tmp)))
                                return -EFAULT;
                        return ksys_msgrcv(first, tmp.msgp, second,
                                           tmp.msgtyp, third);
                }
                default:
                        return ksys_msgrcv(first,
                                           (struct msgbuf __user *) ptr,
                                           second, fifth, third);
                }
        case MSGGET:
                return ksys_msgget((key_t) first, second);
        case MSGCTL:
                return ksys_old_msgctl(first, second,
                                   (struct msqid_ds __user *)ptr);

        case SHMAT:
                switch (version) {
                default: {
                        unsigned long raddr;
                        ret = do_shmat(first, (char __user *)ptr,
                                       second, &raddr, SHMLBA);
                        if (ret)
                                return ret;
                        return put_user(raddr, (unsigned long __user *) third);
                }
                case 1:
                        /*
                         * This was the entry point for kernel-originating calls
                         * from iBCS2 in 2.2 days.
                         */
                        return -EINVAL;
                }
        case SHMDT:
                return ksys_shmdt((char __user *)ptr);
        case SHMGET:
                return ksys_shmget(first, second, third);
        case SHMCTL:
                return ksys_old_shmctl(first, second,
                                   (struct shmid_ds __user *) ptr);
        default:
                return -ENOSYS;
        }
}

SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
                unsigned long, third, void __user *, ptr, long, fifth)
{
        return ksys_ipc(call, first, second, third, ptr, fifth);
}
#endif

#ifdef CONFIG_COMPAT
#include <linux/compat.h>

#ifndef COMPAT_SHMLBA
#define COMPAT_SHMLBA   SHMLBA
#endif

struct compat_ipc_kludge {
        compat_uptr_t msgp;
        compat_long_t msgtyp;
};

#ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
int compat_ksys_ipc(u32 call, int first, int second,
        u32 third, compat_uptr_t ptr, u32 fifth)
{
        int version;
        u32 pad;

        version = call >> 16; /* hack for backward compatibility */
        call &= 0xffff;

        switch (call) {
        case SEMOP:
                /* struct sembuf is the same on 32 and 64bit :)) */
                return ksys_semtimedop(first, compat_ptr(ptr), second, NULL);
        case SEMTIMEDOP:
                if (!IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))
                        return -ENOSYS;
                return compat_ksys_semtimedop(first, compat_ptr(ptr), second,
                                                compat_ptr(fifth));
        case SEMGET:
                return ksys_semget(first, second, third);
        case SEMCTL:
                if (!ptr)
                        return -EINVAL;
                if (get_user(pad, (u32 __user *) compat_ptr(ptr)))
                        return -EFAULT;
                return compat_ksys_old_semctl(first, second, third, pad);

        case MSGSND:
                return compat_ksys_msgsnd(first, ptr, second, third);

        case MSGRCV: {
                void __user *uptr = compat_ptr(ptr);

                if (first < 0 || second < 0)
                        return -EINVAL;

                if (!version) {
                        struct compat_ipc_kludge ipck;
                        if (!uptr)
                                return -EINVAL;
                        if (copy_from_user(&ipck, uptr, sizeof(ipck)))
                                return -EFAULT;
                        return compat_ksys_msgrcv(first, ipck.msgp, second,
                                                 ipck.msgtyp, third);
                }
                return compat_ksys_msgrcv(first, ptr, second, fifth, third);
        }
        case MSGGET:
                return ksys_msgget(first, second);
        case MSGCTL:
                return compat_ksys_old_msgctl(first, second, compat_ptr(ptr));

        case SHMAT: {
                int err;
                unsigned long raddr;

                if (version == 1)
                        return -EINVAL;
                err = do_shmat(first, compat_ptr(ptr), second, &raddr,
                               COMPAT_SHMLBA);
                if (err < 0)
                        return err;
                return put_user(raddr, (compat_ulong_t __user *)compat_ptr(third));
        }
        case SHMDT:
                return ksys_shmdt(compat_ptr(ptr));
        case SHMGET:
                return ksys_shmget(first, (unsigned int)second, third);
        case SHMCTL:
                return compat_ksys_old_shmctl(first, second, compat_ptr(ptr));
        }

        return -ENOSYS;
}

COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
        u32, third, compat_uptr_t, ptr, u32, fifth)
{
        return compat_ksys_ipc(call, first, second, third, ptr, fifth);
}
#endif
#endif