info.c revision c0dd49bdd68c0d758a67d56f07826f3b45cfc664
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
*/
/*
* Copyright (c) 2006 Oracle. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - 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.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*/
#include <sys/rds.h>
#include <sys/ib/clients/rdsv3/rdsv3.h>
/*
* This file implements a getsockopt() call which copies a set of fixed
* sized structs into a user-specified buffer as a means of providing
* read-only information about RDS.
*
* For a given information source there are a given number of fixed sized
* structs at a given time. The structs are only copied if the user-specified
* buffer is big enough. The destination pages that make up the buffer
* are pinned for the duration of the copy.
*
* This gives us the following benefits:
*
* - simple implementation, no copy "position" across multiple calls
* - consistent snapshot of an info source
* - atomic copy works well with whatever locking info source has
* - one portable tool to get rds info across implementations
* - long-lived tool can get info without allocating
*
* at the following costs:
*
* - info source copy must be pinned, may be "large"
*/
static kmutex_t rdsv3_info_lock;
static rdsv3_info_func rdsv3_info_funcs[RDSV3_INFO_LAST - RDSV3_INFO_FIRST + 1];
void
rdsv3_info_register_func(int optname, rdsv3_info_func func)
{
int offset = optname - RDSV3_INFO_FIRST;
ASSERT(optname >= RDSV3_INFO_FIRST && optname <= RDSV3_INFO_LAST);
mutex_enter(&rdsv3_info_lock);
rdsv3_info_funcs[offset] = func;
mutex_exit(&rdsv3_info_lock);
}
/* ARGSUSED */
void
rdsv3_info_deregister_func(int optname, rdsv3_info_func func)
{
int offset = optname - RDSV3_INFO_FIRST;
ASSERT(optname >= RDSV3_INFO_FIRST && optname <= RDSV3_INFO_LAST);
mutex_enter(&rdsv3_info_lock);
rdsv3_info_funcs[offset] = NULL;
mutex_exit(&rdsv3_info_lock);
}
/*
* @optval points to the userspace buffer that the information snapshot
* will be copied into.
*
* @optlen on input is the size of the buffer in userspace. @optlen
* on output is the size of the requested snapshot in bytes.
*
* This function returns -errno if there is a failure, particularly -ENOSPC
* if the given userspace buffer was not large enough to fit the snapshot.
* On success it returns the positive number of bytes of each array element
* in the snapshot.
*/
int
rdsv3_info_getsockopt(struct rsock *sock, int optname, char *optval,
socklen_t *optlen)
{
struct rdsv3_info_iterator iter;
struct rdsv3_info_lengths lens;
rdsv3_info_func func;
func = rdsv3_info_funcs[optname - RDSV3_INFO_FIRST];
if (func == NULL) {
return (-ENOPROTOOPT);
}
if (*optlen == sizeof (struct rdsv3_info_lengths)) {
iter.addr = NULL;
} else {
iter.addr = optval;
}
iter.offset = 0;
func(sock, *optlen, &iter, &lens);
ASSERT(lens.each != 0);
if (iter.addr == NULL) {
bcopy(&lens, optval, sizeof (struct rdsv3_info_lengths));
} else {
*optlen = lens.nr * lens.each;
}
return (0);
}