1 /* 1
2 * Copyright (c) 2006, 2017 Oracle and/or its
3 *
4 * This software is available to you under a c
5 * licenses. You may choose to be licensed un
6 * General Public License (GPL) Version 2, ava
7 * COPYING in the main directory of this sourc
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and bi
11 * without modification, are permitted pro
12 * conditions are met:
13 *
14 * - Redistributions of source code must
15 * copyright notice, this list of condi
16 * disclaimer.
17 *
18 * - Redistributions in binary form must
19 * copyright notice, this list of condi
20 * disclaimer in the documentation and/
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT W
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMIT
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR P
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTH
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER L
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARIS
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR
30 * SOFTWARE.
31 *
32 */
33 #include <linux/kernel.h>
34 #include <linux/slab.h>
35 #include <linux/in.h>
36 #include <net/net_namespace.h>
37 #include <net/netns/generic.h>
38 #include <linux/ipv6.h>
39
40 #include "rds_single_path.h"
41 #include "rds.h"
42 #include "loop.h"
43
44 static DEFINE_SPINLOCK(loop_conns_lock);
45 static LIST_HEAD(loop_conns);
46 static atomic_t rds_loop_unloading = ATOMIC_IN
47
48 static void rds_loop_set_unloading(void)
49 {
50 atomic_set(&rds_loop_unloading, 1);
51 }
52
53 static bool rds_loop_is_unloading(struct rds_c
54 {
55 return atomic_read(&rds_loop_unloading
56 }
57
58 /*
59 * This 'loopback' transport is a special case
60 * and terminate on the same machine.
61 *
62 * Connection build-up notices if the destinat
63 * as a local address by a transport. At that
64 * loopback transport instead of the bound tra
65 *
66 * The loopback transport's sending path just
67 * straight to the receiving path via an embed
68 */
69
70 /*
71 * Usually a message transits both the sender
72 * flows to the receiver. In the loopback cas
73 * is handed the sending conn so the sense of
74 */
75 static int rds_loop_xmit(struct rds_connection
76 unsigned int hdr_off,
77 unsigned int off)
78 {
79 struct scatterlist *sgp = &rm->data.op
80 int ret = sizeof(struct rds_header) +
81 be32_to_cpu(rm->m_inc.
82
83 /* Do not send cong updates to loopbac
84 if (rm->m_inc.i_hdr.h_flags & RDS_FLAG
85 rds_cong_map_updated(conn->c_f
86 ret = min_t(int, ret, sgp->len
87 goto out;
88 }
89
90 BUG_ON(hdr_off || sg || off);
91
92 rds_inc_init(&rm->m_inc, conn, &conn->
93 /* For the embedded inc. Matching put
94 rds_message_addref(rm);
95
96 rds_recv_incoming(conn, &conn->c_laddr
97 GFP_KERNEL);
98
99 rds_send_drop_acked(conn, be64_to_cpu(
100 NULL);
101
102 rds_inc_put(&rm->m_inc);
103 out:
104 return ret;
105 }
106
107 /*
108 * See rds_loop_xmit(). Since our inc is embed
109 * make sure the rm lives at least until the i
110 */
111 static void rds_loop_inc_free(struct rds_incom
112 {
113 struct rds_message *rm = container_of(
114
115 rds_message_put(rm);
116 }
117
118 /* we need to at least give the thread somethi
119 static int rds_loop_recv_path(struct rds_conn_
120 {
121 return 0;
122 }
123
124 struct rds_loop_connection {
125 struct list_head loop_node;
126 struct rds_connection *conn;
127 };
128
129 /*
130 * Even the loopback transport needs to keep t
131 * so it can call rds_conn_destroy() on them o
132 * 1+ loopback addresses (127.*.*.*) so it's n
133 * multiple loopback conns allocated, although
134 */
135 static int rds_loop_conn_alloc(struct rds_conn
136 {
137 struct rds_loop_connection *lc;
138 unsigned long flags;
139
140 lc = kzalloc(sizeof(struct rds_loop_co
141 if (!lc)
142 return -ENOMEM;
143
144 INIT_LIST_HEAD(&lc->loop_node);
145 lc->conn = conn;
146 conn->c_transport_data = lc;
147
148 spin_lock_irqsave(&loop_conns_lock, fl
149 list_add_tail(&lc->loop_node, &loop_co
150 spin_unlock_irqrestore(&loop_conns_loc
151
152 return 0;
153 }
154
155 static void rds_loop_conn_free(void *arg)
156 {
157 struct rds_loop_connection *lc = arg;
158 unsigned long flags;
159
160 rdsdebug("lc %p\n", lc);
161 spin_lock_irqsave(&loop_conns_lock, fl
162 list_del(&lc->loop_node);
163 spin_unlock_irqrestore(&loop_conns_loc
164 kfree(lc);
165 }
166
167 static int rds_loop_conn_path_connect(struct r
168 {
169 rds_connect_complete(cp->cp_conn);
170 return 0;
171 }
172
173 static void rds_loop_conn_path_shutdown(struct
174 {
175 }
176
177 void rds_loop_exit(void)
178 {
179 struct rds_loop_connection *lc, *_lc;
180 LIST_HEAD(tmp_list);
181
182 rds_loop_set_unloading();
183 synchronize_rcu();
184 /* avoid calling conn_destroy with irq
185 spin_lock_irq(&loop_conns_lock);
186 list_splice(&loop_conns, &tmp_list);
187 INIT_LIST_HEAD(&loop_conns);
188 spin_unlock_irq(&loop_conns_lock);
189
190 list_for_each_entry_safe(lc, _lc, &tmp
191 WARN_ON(lc->conn->c_passive);
192 rds_conn_destroy(lc->conn);
193 }
194 }
195
196 static void rds_loop_kill_conns(struct net *ne
197 {
198 struct rds_loop_connection *lc, *_lc;
199 LIST_HEAD(tmp_list);
200
201 spin_lock_irq(&loop_conns_lock);
202 list_for_each_entry_safe(lc, _lc, &loo
203 struct net *c_net = read_pnet(
204
205 if (net != c_net)
206 continue;
207 list_move_tail(&lc->loop_node,
208 }
209 spin_unlock_irq(&loop_conns_lock);
210
211 list_for_each_entry_safe(lc, _lc, &tmp
212 WARN_ON(lc->conn->c_passive);
213 rds_conn_destroy(lc->conn);
214 }
215 }
216
217 static void __net_exit rds_loop_exit_net(struc
218 {
219 rds_loop_kill_conns(net);
220 }
221
222 static struct pernet_operations rds_loop_net_o
223 .exit = rds_loop_exit_net,
224 };
225
226 int rds_loop_net_init(void)
227 {
228 return register_pernet_device(&rds_loo
229 }
230
231 void rds_loop_net_exit(void)
232 {
233 unregister_pernet_device(&rds_loop_net
234 }
235
236 /*
237 * This is missing .xmit_* because loop doesn'
238 * rds_send_xmit() and doesn't call rds_recv_i
239 * .laddr_check are missing because transport.
240 * rds_loop_transport.
241 */
242 struct rds_transport rds_loop_transport = {
243 .xmit = rds_loop_xmi
244 .recv_path = rds_loop_rec
245 .conn_alloc = rds_loop_con
246 .conn_free = rds_loop_con
247 .conn_path_connect = rds_loop_con
248 .conn_path_shutdown = rds_loop_con
249 .inc_copy_to_user = rds_message_
250 .inc_free = rds_loop_inc
251 .t_name = "loopback",
252 .t_type = RDS_TRANS_LO
253 .t_unloading = rds_loop_is_
254 };
255
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