glibc/sysdeps/unix/sysv/linux/msgctl.c

132 lines
4.2 KiB
C

/* Copyright (C) 1995-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <sys/msg.h>
#include <ipc_priv.h>
#include <sysdep.h>
#include <string.h>
#include <sys/syscall.h>
#include <shlib-compat.h>
#include <kernel-features.h>
struct __old_msqid_ds
{
struct __old_ipc_perm msg_perm; /* structure describing operation permission */
struct msg *__msg_first; /* pointer to first message on queue */
struct msg *__msg_last; /* pointer to last message on queue */
__time_t msg_stime; /* time of last msgsnd command */
__time_t msg_rtime; /* time of last msgrcv command */
__time_t msg_ctime; /* time of last change */
struct wait_queue *__wwait; /* ??? */
struct wait_queue *__rwait; /* ??? */
unsigned short int __msg_cbytes; /* current number of bytes on queue */
unsigned short int msg_qnum; /* number of messages currently on queue */
unsigned short int msg_qbytes; /* max number of bytes allowed on queue */
__ipc_pid_t msg_lspid; /* pid of last msgsnd() */
__ipc_pid_t msg_lrpid; /* pid of last msgrcv() */
};
/* Allows to control internal state and destruction of message queue
objects. */
#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
int __old_msgctl (int, int, struct __old_msqid_ds *);
#endif
int __new_msgctl (int, int, struct msqid_ds *);
#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
int
attribute_compat_text_section
__old_msgctl (int msqid, int cmd, struct __old_msqid_ds *buf)
{
return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl, msqid, cmd, 0, buf);
}
compat_symbol (libc, __old_msgctl, msgctl, GLIBC_2_0);
#endif
int
__new_msgctl (int msqid, int cmd, struct msqid_ds *buf)
{
#if __ASSUME_IPC64 > 0
return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
msqid, cmd | __IPC_64, 0, buf);
#else
switch (cmd) {
case MSG_STAT:
case IPC_STAT:
case IPC_SET:
break;
default:
return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
msqid, cmd, 0, buf);
}
{
int result;
struct __old_msqid_ds old;
/* Unfortunately there is no way how to find out for sure whether
we should use old or new msgctl. */
result = INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
msqid, cmd | __IPC_64, 0, buf);
if (result != -1 || errno != EINVAL)
return result;
if (cmd == IPC_SET)
{
old.msg_perm.uid = buf->msg_perm.uid;
old.msg_perm.gid = buf->msg_perm.gid;
old.msg_perm.mode = buf->msg_perm.mode;
old.msg_qbytes = buf->msg_qbytes;
if (old.msg_perm.uid != buf->msg_perm.uid ||
old.msg_perm.gid != buf->msg_perm.gid ||
old.msg_qbytes != buf->msg_qbytes)
{
__set_errno (EINVAL);
return -1;
}
}
result = INLINE_SYSCALL (ipc, 5, IPCOP_msgctl, msqid, cmd, 0, &old);
if (result != -1 && cmd != IPC_SET)
{
memset(buf, 0, sizeof(*buf));
buf->msg_perm.__key = old.msg_perm.__key;
buf->msg_perm.uid = old.msg_perm.uid;
buf->msg_perm.gid = old.msg_perm.gid;
buf->msg_perm.cuid = old.msg_perm.cuid;
buf->msg_perm.cgid = old.msg_perm.cgid;
buf->msg_perm.mode = old.msg_perm.mode;
buf->msg_perm.__seq = old.msg_perm.__seq;
buf->msg_stime = old.msg_stime;
buf->msg_rtime = old.msg_rtime;
buf->msg_ctime = old.msg_ctime;
buf->__msg_cbytes = old.__msg_cbytes;
buf->msg_qnum = old.msg_qnum;
buf->msg_qbytes = old.msg_qbytes;
buf->msg_lspid = old.msg_lspid;
buf->msg_lrpid = old.msg_lrpid;
}
return result;
}
#endif
}
versioned_symbol (libc, __new_msgctl, msgctl, GLIBC_2_2);