diff options
Diffstat (limited to 'lib/libc/net/__cmsg_alignbytes.c')
| -rw-r--r-- | lib/libc/net/__cmsg_alignbytes.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/lib/libc/net/__cmsg_alignbytes.c b/lib/libc/net/__cmsg_alignbytes.c new file mode 100644 index 00000000000..594d34c8882 --- /dev/null +++ b/lib/libc/net/__cmsg_alignbytes.c @@ -0,0 +1,65 @@ +/* $NetBSD: __cmsg_alignbytes.c,v 1.1 2000/03/02 07:41:52 itojun Exp $ */ + +/*- + * Copyright (c) 2000 The NetBSD Foundation, Inc. + * All rights reserved. + * + * This code is derived from software contributed to The NetBSD Foundation + * by Jun-ichiro Hagino. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of The NetBSD Foundation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS + * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <sys/types.h> +#include <sys/param.h> +#include <sys/sysctl.h> +#include <sys/socket.h> + +int +__cmsg_alignbytes() +{ + static int alignbytes = -1; +#ifdef HW_ALIGNBYTES + int mib[2]; + size_t len; + int ret; +#endif + + if (alignbytes > 0) + return alignbytes; + +#ifdef HW_ALIGNBYTES + mib[0] = CTL_HW; + mib[1] = HW_ALIGNBYTES; + len = sizeof(alignbytes); + ret = sysctl(mib, sizeof(mib)/sizeof(mib[0]), (void *)&alignbytes, + &len, NULL, 0); + if (ret >= 0 && alignbytes >= 0) + return alignbytes; +#endif + /* last resort */ + alignbytes = ALIGNBYTES; + return alignbytes; +} |
