xref: /illumos-gate/usr/src/uts/common/io/ib/clients/rdsv3/loop.c (revision 16e76cdd6e3cfaac7d91c3b0644ee1bc6cf52347)
1 /*
2  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
3  */
4 
5 /*
6  * This file contains code imported from the OFED rds source file loop.c
7  * Oracle elects to have and use the contents of loop.c under and governed
8  * by the OpenIB.org BSD license (see below for full license text). However,
9  * the following notice accompanied the original version of this file:
10  */
11 
12 /*
13  * Copyright (c) 2006 Oracle.  All rights reserved.
14  *
15  * This software is available to you under a choice of one of two
16  * licenses.  You may choose to be licensed under the terms of the GNU
17  * General Public License (GPL) Version 2, available from the file
18  * COPYING in the main directory of this source tree, or the
19  * OpenIB.org BSD license below:
20  *
21  *     Redistribution and use in source and binary forms, with or
22  *     without modification, are permitted provided that the following
23  *     conditions are met:
24  *
25  *      - Redistributions of source code must retain the above
26  *        copyright notice, this list of conditions and the following
27  *        disclaimer.
28  *
29  *      - Redistributions in binary form must reproduce the above
30  *        copyright notice, this list of conditions and the following
31  *        disclaimer in the documentation and/or other materials
32  *        provided with the distribution.
33  *
34  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
35  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
36  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
37  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
38  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
39  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
40  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
41  * SOFTWARE.
42  *
43  */
44 #include <sys/rds.h>
45 
46 #include <sys/ib/clients/rdsv3/rdsv3.h>
47 #include <sys/ib/clients/rdsv3/loop.h>
48 #include <sys/ib/clients/rdsv3/rdsv3_debug.h>
49 
50 kmutex_t loop_conns_lock;
51 list_t loop_conns;
52 
53 /*
54  * This 'loopback' transport is a special case for flows that originate
55  * and terminate on the same machine.
56  *
57  * Connection build-up notices if the destination address is thought of
58  * as a local address by a transport.  At that time it decides to use the
59  * loopback transport instead of the bound transport of the sending socket.
60  *
61  * The loopback transport's sending path just hands the sent rds_message
62  * straight to the receiving path via an embedded rds_incoming.
63  */
64 
65 /*
66  * Usually a message transits both the sender and receiver's conns as it
67  * flows to the receiver.  In the loopback case, though, the receive path
68  * is handed the sending conn so the sense of the addresses is reversed.
69  */
70 static int
71 rdsv3_loop_xmit(struct rdsv3_connection *conn, struct rdsv3_message *rm,
72     unsigned int hdr_off, unsigned int sg,
73     unsigned int off)
74 {
75 	/* Do not send cong updates to loopback */
76 	if (rm->m_inc.i_hdr.h_flags & RDSV3_FLAG_CONG_BITMAP) {
77 		rdsv3_cong_map_updated(conn->c_fcong, ~(uint64_t)0);
78 		return (sizeof (struct rdsv3_header) + RDSV3_CONG_MAP_BYTES);
79 	}
80 	ASSERT(!(hdr_off || sg || off));
81 
82 	RDSV3_DPRINTF4("rdsv3_loop_xmit", "Enter(conn: %p, rm: %p)", conn, rm);
83 
84 	rdsv3_inc_init(&rm->m_inc, conn, conn->c_laddr);
85 	/* For the embedded inc. Matching put is in loop_inc_free() */
86 	rdsv3_message_addref(rm);
87 
88 	rdsv3_recv_incoming(conn, conn->c_laddr, conn->c_faddr, &rm->m_inc,
89 	    KM_NOSLEEP);
90 
91 	rdsv3_send_drop_acked(conn, ntohll(rm->m_inc.i_hdr.h_sequence),
92 	    NULL);
93 
94 	rdsv3_inc_put(&rm->m_inc);
95 
96 	RDSV3_DPRINTF4("rdsv3_loop_xmit", "Return(conn: %p, rm: %p)", conn, rm);
97 
98 	return (sizeof (struct rdsv3_header) +
99 	    ntohl(rm->m_inc.i_hdr.h_len));
100 }
101 
102 /*
103  * See rds_loop_xmit(). Since our inc is embedded in the rm, we
104  * make sure the rm lives at least until the inc is done.
105  */
106 static void
107 rdsv3_loop_inc_free(struct rdsv3_incoming *inc)
108 {
109 	struct rdsv3_message *rm = container_of(inc, struct rdsv3_message,
110 	    m_inc);
111 	rdsv3_message_put(rm);
112 }
113 
114 static int
115 rdsv3_loop_xmit_cong_map(struct rdsv3_connection *conn,
116     struct rdsv3_cong_map *map,
117     unsigned long offset)
118 {
119 	RDSV3_DPRINTF4("rdsv3_loop_xmit_cong_map", "Enter(conn: %p)", conn);
120 
121 	ASSERT(!offset);
122 	ASSERT(map == conn->c_lcong);
123 
124 	rdsv3_cong_map_updated(conn->c_fcong, ~(uint64_t)0);
125 
126 	RDSV3_DPRINTF4("rdsv3_loop_xmit_cong_map", "Return(conn: %p)", conn);
127 
128 	return (sizeof (struct rdsv3_header) + RDSV3_CONG_MAP_BYTES);
129 }
130 
131 /* we need to at least give the thread something to succeed */
132 /* ARGSUSED */
133 static int
134 rdsv3_loop_recv(struct rdsv3_connection *conn)
135 {
136 	return (0);
137 }
138 
139 struct rdsv3_loop_connection {
140 	struct list_node loop_node;
141 	struct rdsv3_connection *conn;
142 };
143 
144 /*
145  * Even the loopback transport needs to keep track of its connections,
146  * so it can call rdsv3_conn_destroy() on them on exit. N.B. there are
147  * 1+ loopback addresses (127.*.*.*) so it's not a bug to have
148  * multiple loopback conns allocated, although rather useless.
149  */
150 /* ARGSUSED */
151 static int
152 rdsv3_loop_conn_alloc(struct rdsv3_connection *conn, int gfp)
153 {
154 	struct rdsv3_loop_connection *lc;
155 
156 	RDSV3_DPRINTF4("rdsv3_loop_conn_alloc", "Enter(conn: %p)", conn);
157 
158 	lc = kmem_zalloc(sizeof (struct rdsv3_loop_connection), KM_NOSLEEP);
159 	if (!lc)
160 		return (-ENOMEM);
161 
162 	list_link_init(&lc->loop_node);
163 	lc->conn = conn;
164 	conn->c_transport_data = lc;
165 
166 	mutex_enter(&loop_conns_lock);
167 	list_insert_tail(&loop_conns, lc);
168 	mutex_exit(&loop_conns_lock);
169 
170 	RDSV3_DPRINTF4("rdsv3_loop_conn_alloc", "Return(conn: %p)", conn);
171 
172 	return (0);
173 }
174 
175 static void
176 rdsv3_loop_conn_free(void *arg)
177 {
178 	struct rdsv3_loop_connection *lc = arg;
179 	RDSV3_DPRINTF5("rdsv3_loop_conn_free", "lc %p\n", lc);
180 	list_remove_node(&lc->loop_node);
181 	kmem_free(lc, sizeof (struct rdsv3_loop_connection));
182 }
183 
184 static int
185 rdsv3_loop_conn_connect(struct rdsv3_connection *conn)
186 {
187 	rdsv3_connect_complete(conn);
188 	return (0);
189 }
190 
191 /* ARGSUSED */
192 static void
193 rdsv3_loop_conn_shutdown(struct rdsv3_connection *conn)
194 {
195 }
196 
197 void
198 rdsv3_loop_exit(void)
199 {
200 	struct rdsv3_loop_connection *lc, *_lc;
201 	list_t tmp_list;
202 
203 	RDSV3_DPRINTF4("rdsv3_loop_exit", "Enter");
204 
205 	list_create(&tmp_list, sizeof (struct rdsv3_loop_connection),
206 	    offsetof(struct rdsv3_loop_connection, loop_node));
207 
208 	/* avoid calling conn_destroy with irqs off */
209 	mutex_enter(&loop_conns_lock);
210 	list_splice(&loop_conns, &tmp_list);
211 	mutex_exit(&loop_conns_lock);
212 
213 	RDSV3_FOR_EACH_LIST_NODE_SAFE(lc, _lc, &tmp_list, loop_node) {
214 		ASSERT(!lc->conn->c_passive);
215 		rdsv3_conn_destroy(lc->conn);
216 	}
217 
218 	list_destroy(&loop_conns);
219 	mutex_destroy(&loop_conns_lock);
220 
221 	RDSV3_DPRINTF4("rdsv3_loop_exit", "Return");
222 }
223 
224 /*
225  * This is missing .xmit_* because loop doesn't go through generic
226  * rdsv3_send_xmit() and doesn't call rdsv3_recv_incoming().  .listen_stop and
227  * .laddr_check are missing because transport.c doesn't iterate over
228  * rdsv3_loop_transport.
229  */
230 #ifndef __lock_lint
231 struct rdsv3_transport rdsv3_loop_transport = {
232 	.xmit			= rdsv3_loop_xmit,
233 	.xmit_cong_map		= rdsv3_loop_xmit_cong_map,
234 	.recv			= rdsv3_loop_recv,
235 	.conn_alloc		= rdsv3_loop_conn_alloc,
236 	.conn_free		= rdsv3_loop_conn_free,
237 	.conn_connect		= rdsv3_loop_conn_connect,
238 	.conn_shutdown		= rdsv3_loop_conn_shutdown,
239 	.inc_copy_to_user	= rdsv3_message_inc_copy_to_user,
240 	.inc_free		= rdsv3_loop_inc_free,
241 	.t_name			= "loopback",
242 };
243 #else
244 struct rdsv3_transport rdsv3_loop_transport;
245 #endif
246