Linux Audio

Check our new training course

Loading...
v3.5.6
  1/*
  2 * Copyright (c) 2006 Oracle.  All rights reserved.
  3 *
  4 * This software is available to you under a choice of one of two
  5 * licenses.  You may choose to be licensed under the terms of the GNU
  6 * General Public License (GPL) Version 2, available from the file
  7 * COPYING in the main directory of this source tree, or the
  8 * OpenIB.org BSD license below:
  9 *
 10 *     Redistribution and use in source and binary forms, with or
 11 *     without modification, are permitted provided that the following
 12 *     conditions are met:
 13 *
 14 *      - Redistributions of source code must retain the above
 15 *        copyright notice, this list of conditions and the following
 16 *        disclaimer.
 17 *
 18 *      - Redistributions in binary form must reproduce the above
 19 *        copyright notice, this list of conditions and the following
 20 *        disclaimer in the documentation and/or other materials
 21 *        provided with the distribution.
 22 *
 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 30 * SOFTWARE.
 31 *
 32 */
 33#include <linux/kernel.h>
 34#include <linux/slab.h>
 35#include <linux/in.h>
 36
 
 37#include "rds.h"
 38#include "loop.h"
 39
 40static DEFINE_SPINLOCK(loop_conns_lock);
 41static LIST_HEAD(loop_conns);
 42
 43/*
 44 * This 'loopback' transport is a special case for flows that originate
 45 * and terminate on the same machine.
 46 *
 47 * Connection build-up notices if the destination address is thought of
 48 * as a local address by a transport.  At that time it decides to use the
 49 * loopback transport instead of the bound transport of the sending socket.
 50 *
 51 * The loopback transport's sending path just hands the sent rds_message
 52 * straight to the receiving path via an embedded rds_incoming.
 53 */
 54
 55/*
 56 * Usually a message transits both the sender and receiver's conns as it
 57 * flows to the receiver.  In the loopback case, though, the receive path
 58 * is handed the sending conn so the sense of the addresses is reversed.
 59 */
 60static int rds_loop_xmit(struct rds_connection *conn, struct rds_message *rm,
 61			 unsigned int hdr_off, unsigned int sg,
 62			 unsigned int off)
 63{
 64	struct scatterlist *sgp = &rm->data.op_sg[sg];
 65	int ret = sizeof(struct rds_header) +
 66			be32_to_cpu(rm->m_inc.i_hdr.h_len);
 67
 68	/* Do not send cong updates to loopback */
 69	if (rm->m_inc.i_hdr.h_flags & RDS_FLAG_CONG_BITMAP) {
 70		rds_cong_map_updated(conn->c_fcong, ~(u64) 0);
 71		ret = min_t(int, ret, sgp->length - conn->c_xmit_data_off);
 72		goto out;
 73	}
 74
 75	BUG_ON(hdr_off || sg || off);
 76
 77	rds_inc_init(&rm->m_inc, conn, conn->c_laddr);
 78	/* For the embedded inc. Matching put is in loop_inc_free() */
 79	rds_message_addref(rm);
 80
 81	rds_recv_incoming(conn, conn->c_laddr, conn->c_faddr, &rm->m_inc,
 82			  GFP_KERNEL);
 83
 84	rds_send_drop_acked(conn, be64_to_cpu(rm->m_inc.i_hdr.h_sequence),
 85			    NULL);
 86
 87	rds_inc_put(&rm->m_inc);
 88out:
 89	return ret;
 90}
 91
 92/*
 93 * See rds_loop_xmit(). Since our inc is embedded in the rm, we
 94 * make sure the rm lives at least until the inc is done.
 95 */
 96static void rds_loop_inc_free(struct rds_incoming *inc)
 97{
 98        struct rds_message *rm = container_of(inc, struct rds_message, m_inc);
 99        rds_message_put(rm);
 
100}
101
102/* we need to at least give the thread something to succeed */
103static int rds_loop_recv(struct rds_connection *conn)
104{
105	return 0;
106}
107
108struct rds_loop_connection {
109	struct list_head loop_node;
110	struct rds_connection *conn;
111};
112
113/*
114 * Even the loopback transport needs to keep track of its connections,
115 * so it can call rds_conn_destroy() on them on exit. N.B. there are
116 * 1+ loopback addresses (127.*.*.*) so it's not a bug to have
117 * multiple loopback conns allocated, although rather useless.
118 */
119static int rds_loop_conn_alloc(struct rds_connection *conn, gfp_t gfp)
120{
121	struct rds_loop_connection *lc;
122	unsigned long flags;
123
124	lc = kzalloc(sizeof(struct rds_loop_connection), gfp);
125	if (!lc)
126		return -ENOMEM;
127
128	INIT_LIST_HEAD(&lc->loop_node);
129	lc->conn = conn;
130	conn->c_transport_data = lc;
131
132	spin_lock_irqsave(&loop_conns_lock, flags);
133	list_add_tail(&lc->loop_node, &loop_conns);
134	spin_unlock_irqrestore(&loop_conns_lock, flags);
135
136	return 0;
137}
138
139static void rds_loop_conn_free(void *arg)
140{
141	struct rds_loop_connection *lc = arg;
142	unsigned long flags;
143
144	rdsdebug("lc %p\n", lc);
145	spin_lock_irqsave(&loop_conns_lock, flags);
146	list_del(&lc->loop_node);
147	spin_unlock_irqrestore(&loop_conns_lock, flags);
148	kfree(lc);
149}
150
151static int rds_loop_conn_connect(struct rds_connection *conn)
152{
153	rds_connect_complete(conn);
154	return 0;
155}
156
157static void rds_loop_conn_shutdown(struct rds_connection *conn)
158{
159}
160
161void rds_loop_exit(void)
162{
163	struct rds_loop_connection *lc, *_lc;
164	LIST_HEAD(tmp_list);
165
166	/* avoid calling conn_destroy with irqs off */
167	spin_lock_irq(&loop_conns_lock);
168	list_splice(&loop_conns, &tmp_list);
169	INIT_LIST_HEAD(&loop_conns);
170	spin_unlock_irq(&loop_conns_lock);
171
172	list_for_each_entry_safe(lc, _lc, &tmp_list, loop_node) {
173		WARN_ON(lc->conn->c_passive);
174		rds_conn_destroy(lc->conn);
175	}
176}
177
178/*
179 * This is missing .xmit_* because loop doesn't go through generic
180 * rds_send_xmit() and doesn't call rds_recv_incoming().  .listen_stop and
181 * .laddr_check are missing because transport.c doesn't iterate over
182 * rds_loop_transport.
183 */
184struct rds_transport rds_loop_transport = {
185	.xmit			= rds_loop_xmit,
186	.recv			= rds_loop_recv,
187	.conn_alloc		= rds_loop_conn_alloc,
188	.conn_free		= rds_loop_conn_free,
189	.conn_connect		= rds_loop_conn_connect,
190	.conn_shutdown		= rds_loop_conn_shutdown,
191	.inc_copy_to_user	= rds_message_inc_copy_to_user,
192	.inc_free		= rds_loop_inc_free,
193	.t_name			= "loopback",
194};
v4.17
  1/*
  2 * Copyright (c) 2006 Oracle.  All rights reserved.
  3 *
  4 * This software is available to you under a choice of one of two
  5 * licenses.  You may choose to be licensed under the terms of the GNU
  6 * General Public License (GPL) Version 2, available from the file
  7 * COPYING in the main directory of this source tree, or the
  8 * OpenIB.org BSD license below:
  9 *
 10 *     Redistribution and use in source and binary forms, with or
 11 *     without modification, are permitted provided that the following
 12 *     conditions are met:
 13 *
 14 *      - Redistributions of source code must retain the above
 15 *        copyright notice, this list of conditions and the following
 16 *        disclaimer.
 17 *
 18 *      - Redistributions in binary form must reproduce the above
 19 *        copyright notice, this list of conditions and the following
 20 *        disclaimer in the documentation and/or other materials
 21 *        provided with the distribution.
 22 *
 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 30 * SOFTWARE.
 31 *
 32 */
 33#include <linux/kernel.h>
 34#include <linux/slab.h>
 35#include <linux/in.h>
 36
 37#include "rds_single_path.h"
 38#include "rds.h"
 39#include "loop.h"
 40
 41static DEFINE_SPINLOCK(loop_conns_lock);
 42static LIST_HEAD(loop_conns);
 43
 44/*
 45 * This 'loopback' transport is a special case for flows that originate
 46 * and terminate on the same machine.
 47 *
 48 * Connection build-up notices if the destination address is thought of
 49 * as a local address by a transport.  At that time it decides to use the
 50 * loopback transport instead of the bound transport of the sending socket.
 51 *
 52 * The loopback transport's sending path just hands the sent rds_message
 53 * straight to the receiving path via an embedded rds_incoming.
 54 */
 55
 56/*
 57 * Usually a message transits both the sender and receiver's conns as it
 58 * flows to the receiver.  In the loopback case, though, the receive path
 59 * is handed the sending conn so the sense of the addresses is reversed.
 60 */
 61static int rds_loop_xmit(struct rds_connection *conn, struct rds_message *rm,
 62			 unsigned int hdr_off, unsigned int sg,
 63			 unsigned int off)
 64{
 65	struct scatterlist *sgp = &rm->data.op_sg[sg];
 66	int ret = sizeof(struct rds_header) +
 67			be32_to_cpu(rm->m_inc.i_hdr.h_len);
 68
 69	/* Do not send cong updates to loopback */
 70	if (rm->m_inc.i_hdr.h_flags & RDS_FLAG_CONG_BITMAP) {
 71		rds_cong_map_updated(conn->c_fcong, ~(u64) 0);
 72		ret = min_t(int, ret, sgp->length - conn->c_xmit_data_off);
 73		goto out;
 74	}
 75
 76	BUG_ON(hdr_off || sg || off);
 77
 78	rds_inc_init(&rm->m_inc, conn, conn->c_laddr);
 79	/* For the embedded inc. Matching put is in loop_inc_free() */
 80	rds_message_addref(rm);
 81
 82	rds_recv_incoming(conn, conn->c_laddr, conn->c_faddr, &rm->m_inc,
 83			  GFP_KERNEL);
 84
 85	rds_send_drop_acked(conn, be64_to_cpu(rm->m_inc.i_hdr.h_sequence),
 86			    NULL);
 87
 88	rds_inc_put(&rm->m_inc);
 89out:
 90	return ret;
 91}
 92
 93/*
 94 * See rds_loop_xmit(). Since our inc is embedded in the rm, we
 95 * make sure the rm lives at least until the inc is done.
 96 */
 97static void rds_loop_inc_free(struct rds_incoming *inc)
 98{
 99	struct rds_message *rm = container_of(inc, struct rds_message, m_inc);
100
101	rds_message_put(rm);
102}
103
104/* we need to at least give the thread something to succeed */
105static int rds_loop_recv_path(struct rds_conn_path *cp)
106{
107	return 0;
108}
109
110struct rds_loop_connection {
111	struct list_head loop_node;
112	struct rds_connection *conn;
113};
114
115/*
116 * Even the loopback transport needs to keep track of its connections,
117 * so it can call rds_conn_destroy() on them on exit. N.B. there are
118 * 1+ loopback addresses (127.*.*.*) so it's not a bug to have
119 * multiple loopback conns allocated, although rather useless.
120 */
121static int rds_loop_conn_alloc(struct rds_connection *conn, gfp_t gfp)
122{
123	struct rds_loop_connection *lc;
124	unsigned long flags;
125
126	lc = kzalloc(sizeof(struct rds_loop_connection), gfp);
127	if (!lc)
128		return -ENOMEM;
129
130	INIT_LIST_HEAD(&lc->loop_node);
131	lc->conn = conn;
132	conn->c_transport_data = lc;
133
134	spin_lock_irqsave(&loop_conns_lock, flags);
135	list_add_tail(&lc->loop_node, &loop_conns);
136	spin_unlock_irqrestore(&loop_conns_lock, flags);
137
138	return 0;
139}
140
141static void rds_loop_conn_free(void *arg)
142{
143	struct rds_loop_connection *lc = arg;
144	unsigned long flags;
145
146	rdsdebug("lc %p\n", lc);
147	spin_lock_irqsave(&loop_conns_lock, flags);
148	list_del(&lc->loop_node);
149	spin_unlock_irqrestore(&loop_conns_lock, flags);
150	kfree(lc);
151}
152
153static int rds_loop_conn_path_connect(struct rds_conn_path *cp)
154{
155	rds_connect_complete(cp->cp_conn);
156	return 0;
157}
158
159static void rds_loop_conn_path_shutdown(struct rds_conn_path *cp)
160{
161}
162
163void rds_loop_exit(void)
164{
165	struct rds_loop_connection *lc, *_lc;
166	LIST_HEAD(tmp_list);
167
168	/* avoid calling conn_destroy with irqs off */
169	spin_lock_irq(&loop_conns_lock);
170	list_splice(&loop_conns, &tmp_list);
171	INIT_LIST_HEAD(&loop_conns);
172	spin_unlock_irq(&loop_conns_lock);
173
174	list_for_each_entry_safe(lc, _lc, &tmp_list, loop_node) {
175		WARN_ON(lc->conn->c_passive);
176		rds_conn_destroy(lc->conn);
177	}
178}
179
180/*
181 * This is missing .xmit_* because loop doesn't go through generic
182 * rds_send_xmit() and doesn't call rds_recv_incoming().  .listen_stop and
183 * .laddr_check are missing because transport.c doesn't iterate over
184 * rds_loop_transport.
185 */
186struct rds_transport rds_loop_transport = {
187	.xmit			= rds_loop_xmit,
188	.recv_path		= rds_loop_recv_path,
189	.conn_alloc		= rds_loop_conn_alloc,
190	.conn_free		= rds_loop_conn_free,
191	.conn_path_connect	= rds_loop_conn_path_connect,
192	.conn_path_shutdown	= rds_loop_conn_path_shutdown,
193	.inc_copy_to_user	= rds_message_inc_copy_to_user,
194	.inc_free		= rds_loop_inc_free,
195	.t_name			= "loopback",
196};