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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 | |
40 | static DEFINE_SPINLOCK(loop_conns_lock); |
41 | static 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 | */ |
60 | static 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 | BUG_ON(hdr_off || sg || off); |
65 | |
66 | rds_inc_init(&rm->m_inc, conn, conn->c_laddr); |
67 | rds_message_addref(rm); /* for the inc */ |
68 | |
69 | rds_recv_incoming(conn, conn->c_laddr, conn->c_faddr, &rm->m_inc, |
70 | GFP_KERNEL, KM_USER0); |
71 | |
72 | rds_send_drop_acked(conn, be64_to_cpu(rm->m_inc.i_hdr.h_sequence), |
73 | NULL); |
74 | |
75 | rds_inc_put(&rm->m_inc); |
76 | |
77 | return sizeof(struct rds_header) + be32_to_cpu(rm->m_inc.i_hdr.h_len); |
78 | } |
79 | |
80 | static int rds_loop_xmit_cong_map(struct rds_connection *conn, |
81 | struct rds_cong_map *map, |
82 | unsigned long offset) |
83 | { |
84 | BUG_ON(offset); |
85 | BUG_ON(map != conn->c_lcong); |
86 | |
87 | rds_cong_map_updated(conn->c_fcong, ~(u64) 0); |
88 | |
89 | return sizeof(struct rds_header) + RDS_CONG_MAP_BYTES; |
90 | } |
91 | |
92 | /* we need to at least give the thread something to succeed */ |
93 | static int rds_loop_recv(struct rds_connection *conn) |
94 | { |
95 | return 0; |
96 | } |
97 | |
98 | struct rds_loop_connection { |
99 | struct list_head loop_node; |
100 | struct rds_connection *conn; |
101 | }; |
102 | |
103 | /* |
104 | * Even the loopback transport needs to keep track of its connections, |
105 | * so it can call rds_conn_destroy() on them on exit. N.B. there are |
106 | * 1+ loopback addresses (127.*.*.*) so it's not a bug to have |
107 | * multiple loopback conns allocated, although rather useless. |
108 | */ |
109 | static int rds_loop_conn_alloc(struct rds_connection *conn, gfp_t gfp) |
110 | { |
111 | struct rds_loop_connection *lc; |
112 | unsigned long flags; |
113 | |
114 | lc = kzalloc(sizeof(struct rds_loop_connection), GFP_KERNEL); |
115 | if (lc == NULL) |
116 | return -ENOMEM; |
117 | |
118 | INIT_LIST_HEAD(&lc->loop_node); |
119 | lc->conn = conn; |
120 | conn->c_transport_data = lc; |
121 | |
122 | spin_lock_irqsave(&loop_conns_lock, flags); |
123 | list_add_tail(&lc->loop_node, &loop_conns); |
124 | spin_unlock_irqrestore(&loop_conns_lock, flags); |
125 | |
126 | return 0; |
127 | } |
128 | |
129 | static void rds_loop_conn_free(void *arg) |
130 | { |
131 | struct rds_loop_connection *lc = arg; |
132 | rdsdebug("lc %p\n", lc); |
133 | list_del(&lc->loop_node); |
134 | kfree(lc); |
135 | } |
136 | |
137 | static int rds_loop_conn_connect(struct rds_connection *conn) |
138 | { |
139 | rds_connect_complete(conn); |
140 | return 0; |
141 | } |
142 | |
143 | static void rds_loop_conn_shutdown(struct rds_connection *conn) |
144 | { |
145 | } |
146 | |
147 | void rds_loop_exit(void) |
148 | { |
149 | struct rds_loop_connection *lc, *_lc; |
150 | LIST_HEAD(tmp_list); |
151 | |
152 | /* avoid calling conn_destroy with irqs off */ |
153 | spin_lock_irq(&loop_conns_lock); |
154 | list_splice(&loop_conns, &tmp_list); |
155 | INIT_LIST_HEAD(&loop_conns); |
156 | spin_unlock_irq(&loop_conns_lock); |
157 | |
158 | list_for_each_entry_safe(lc, _lc, &tmp_list, loop_node) { |
159 | WARN_ON(lc->conn->c_passive); |
160 | rds_conn_destroy(lc->conn); |
161 | } |
162 | } |
163 | |
164 | /* |
165 | * This is missing .xmit_* because loop doesn't go through generic |
166 | * rds_send_xmit() and doesn't call rds_recv_incoming(). .listen_stop and |
167 | * .laddr_check are missing because transport.c doesn't iterate over |
168 | * rds_loop_transport. |
169 | */ |
170 | struct rds_transport rds_loop_transport = { |
171 | .xmit = rds_loop_xmit, |
172 | .xmit_cong_map = rds_loop_xmit_cong_map, |
173 | .recv = rds_loop_recv, |
174 | .conn_alloc = rds_loop_conn_alloc, |
175 | .conn_free = rds_loop_conn_free, |
176 | .conn_connect = rds_loop_conn_connect, |
177 | .conn_shutdown = rds_loop_conn_shutdown, |
178 | .inc_copy_to_user = rds_message_inc_copy_to_user, |
179 | .inc_purge = rds_message_inc_purge, |
180 | .inc_free = rds_message_inc_free, |
181 | .t_name = "loopback", |
182 | }; |
183 |
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9