/net/rds/transport.c
http://github.com/mirrors/linux · C · 161 lines · 97 code · 26 blank · 38 comment · 21 complexity · 37c1efa6d944a65cdbd9cd49d15da582 MD5 · raw file
- /*
- * Copyright (c) 2006, 2017 Oracle and/or its affiliates. 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 <linux/kernel.h>
- #include <linux/module.h>
- #include <linux/in.h>
- #include <linux/ipv6.h>
- #include "rds.h"
- #include "loop.h"
- static struct rds_transport *transports[RDS_TRANS_COUNT];
- static DECLARE_RWSEM(rds_trans_sem);
- void rds_trans_register(struct rds_transport *trans)
- {
- BUG_ON(strlen(trans->t_name) + 1 > TRANSNAMSIZ);
- down_write(&rds_trans_sem);
- if (transports[trans->t_type])
- printk(KERN_ERR "RDS Transport type %d already registered\n",
- trans->t_type);
- else {
- transports[trans->t_type] = trans;
- printk(KERN_INFO "Registered RDS/%s transport\n", trans->t_name);
- }
- up_write(&rds_trans_sem);
- }
- EXPORT_SYMBOL_GPL(rds_trans_register);
- void rds_trans_unregister(struct rds_transport *trans)
- {
- down_write(&rds_trans_sem);
- transports[trans->t_type] = NULL;
- printk(KERN_INFO "Unregistered RDS/%s transport\n", trans->t_name);
- up_write(&rds_trans_sem);
- }
- EXPORT_SYMBOL_GPL(rds_trans_unregister);
- void rds_trans_put(struct rds_transport *trans)
- {
- if (trans)
- module_put(trans->t_owner);
- }
- struct rds_transport *rds_trans_get_preferred(struct net *net,
- const struct in6_addr *addr,
- __u32 scope_id)
- {
- struct rds_transport *ret = NULL;
- struct rds_transport *trans;
- unsigned int i;
- if (ipv6_addr_v4mapped(addr)) {
- if (*(u_int8_t *)&addr->s6_addr32[3] == IN_LOOPBACKNET)
- return &rds_loop_transport;
- } else if (ipv6_addr_loopback(addr)) {
- return &rds_loop_transport;
- }
- down_read(&rds_trans_sem);
- for (i = 0; i < RDS_TRANS_COUNT; i++) {
- trans = transports[i];
- if (trans && (trans->laddr_check(net, addr, scope_id) == 0) &&
- (!trans->t_owner || try_module_get(trans->t_owner))) {
- ret = trans;
- break;
- }
- }
- up_read(&rds_trans_sem);
- return ret;
- }
- struct rds_transport *rds_trans_get(int t_type)
- {
- struct rds_transport *ret = NULL;
- struct rds_transport *trans;
- unsigned int i;
- down_read(&rds_trans_sem);
- for (i = 0; i < RDS_TRANS_COUNT; i++) {
- trans = transports[i];
- if (trans && trans->t_type == t_type &&
- (!trans->t_owner || try_module_get(trans->t_owner))) {
- ret = trans;
- break;
- }
- }
- up_read(&rds_trans_sem);
- return ret;
- }
- /*
- * This returns the number of stats entries in the snapshot and only
- * copies them using the iter if there is enough space for them. The
- * caller passes in the global stats so that we can size and copy while
- * holding the lock.
- */
- unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter,
- unsigned int avail)
- {
- struct rds_transport *trans;
- unsigned int total = 0;
- unsigned int part;
- int i;
- rds_info_iter_unmap(iter);
- down_read(&rds_trans_sem);
- for (i = 0; i < RDS_TRANS_COUNT; i++) {
- trans = transports[i];
- if (!trans || !trans->stats_info_copy)
- continue;
- part = trans->stats_info_copy(iter, avail);
- avail -= min(avail, part);
- total += part;
- }
- up_read(&rds_trans_sem);
- return total;
- }