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 #include <linux/module.h>
37 #include <net/tcp.h>
38
39 #include "rds.h"
40 #include "tcp.h"
41
42 /* only for info exporting */
43 static DEFINE_SPINLOCK(rds_tcp_tc_list_lock);
44 static LIST_HEAD(rds_tcp_tc_list);
45 static unsigned int rds_tcp_tc_count;
46
47 /* Track rds_tcp_connection structs so they can be cleaned up */
48 static DEFINE_SPINLOCK(rds_tcp_conn_lock);
49 static LIST_HEAD(rds_tcp_conn_list);
50
51 static struct kmem_cache *rds_tcp_conn_slab;
52
53 #define RDS_TCP_DEFAULT_BUFSIZE (128 * 1024)
54
55 /* doing it this way avoids calling tcp_sk() */
rds_tcp_nonagle(struct socket * sock)56 void rds_tcp_nonagle(struct socket *sock)
57 {
58 mm_segment_t oldfs = get_fs();
59 int val = 1;
60
61 set_fs(KERNEL_DS);
62 sock->ops->setsockopt(sock, SOL_TCP, TCP_NODELAY, (char __user *)&val,
63 sizeof(val));
64 set_fs(oldfs);
65 }
66
rds_tcp_tune(struct socket * sock)67 void rds_tcp_tune(struct socket *sock)
68 {
69 struct sock *sk = sock->sk;
70
71 rds_tcp_nonagle(sock);
72
73 /*
74 * We're trying to saturate gigabit with the default,
75 * see svc_sock_setbufsize().
76 */
77 lock_sock(sk);
78 sk->sk_sndbuf = RDS_TCP_DEFAULT_BUFSIZE;
79 sk->sk_rcvbuf = RDS_TCP_DEFAULT_BUFSIZE;
80 sk->sk_userlocks |= SOCK_SNDBUF_LOCK|SOCK_RCVBUF_LOCK;
81 release_sock(sk);
82 }
83
rds_tcp_snd_nxt(struct rds_tcp_connection * tc)84 u32 rds_tcp_snd_nxt(struct rds_tcp_connection *tc)
85 {
86 return tcp_sk(tc->t_sock->sk)->snd_nxt;
87 }
88
rds_tcp_snd_una(struct rds_tcp_connection * tc)89 u32 rds_tcp_snd_una(struct rds_tcp_connection *tc)
90 {
91 return tcp_sk(tc->t_sock->sk)->snd_una;
92 }
93
rds_tcp_restore_callbacks(struct socket * sock,struct rds_tcp_connection * tc)94 void rds_tcp_restore_callbacks(struct socket *sock,
95 struct rds_tcp_connection *tc)
96 {
97 rdsdebug("restoring sock %p callbacks from tc %p\n", sock, tc);
98 write_lock_bh(&sock->sk->sk_callback_lock);
99
100 /* done under the callback_lock to serialize with write_space */
101 spin_lock(&rds_tcp_tc_list_lock);
102 list_del_init(&tc->t_list_item);
103 rds_tcp_tc_count--;
104 spin_unlock(&rds_tcp_tc_list_lock);
105
106 tc->t_sock = NULL;
107
108 sock->sk->sk_write_space = tc->t_orig_write_space;
109 sock->sk->sk_data_ready = tc->t_orig_data_ready;
110 sock->sk->sk_state_change = tc->t_orig_state_change;
111 sock->sk->sk_user_data = NULL;
112
113 write_unlock_bh(&sock->sk->sk_callback_lock);
114 }
115
116 /*
117 * This is the only path that sets tc->t_sock. Send and receive trust that
118 * it is set. The RDS_CONN_CONNECTED bit protects those paths from being
119 * called while it isn't set.
120 */
rds_tcp_set_callbacks(struct socket * sock,struct rds_connection * conn)121 void rds_tcp_set_callbacks(struct socket *sock, struct rds_connection *conn)
122 {
123 struct rds_tcp_connection *tc = conn->c_transport_data;
124
125 rdsdebug("setting sock %p callbacks to tc %p\n", sock, tc);
126 write_lock_bh(&sock->sk->sk_callback_lock);
127
128 /* done under the callback_lock to serialize with write_space */
129 spin_lock(&rds_tcp_tc_list_lock);
130 list_add_tail(&tc->t_list_item, &rds_tcp_tc_list);
131 rds_tcp_tc_count++;
132 spin_unlock(&rds_tcp_tc_list_lock);
133
134 /* accepted sockets need our listen data ready undone */
135 if (sock->sk->sk_data_ready == rds_tcp_listen_data_ready)
136 sock->sk->sk_data_ready = sock->sk->sk_user_data;
137
138 tc->t_sock = sock;
139 tc->conn = conn;
140 tc->t_orig_data_ready = sock->sk->sk_data_ready;
141 tc->t_orig_write_space = sock->sk->sk_write_space;
142 tc->t_orig_state_change = sock->sk->sk_state_change;
143
144 sock->sk->sk_user_data = conn;
145 sock->sk->sk_data_ready = rds_tcp_data_ready;
146 sock->sk->sk_write_space = rds_tcp_write_space;
147 sock->sk->sk_state_change = rds_tcp_state_change;
148
149 write_unlock_bh(&sock->sk->sk_callback_lock);
150 }
151
rds_tcp_tc_info(struct socket * sock,unsigned int len,struct rds_info_iterator * iter,struct rds_info_lengths * lens)152 static void rds_tcp_tc_info(struct socket *sock, unsigned int len,
153 struct rds_info_iterator *iter,
154 struct rds_info_lengths *lens)
155 {
156 struct rds_info_tcp_socket tsinfo;
157 struct rds_tcp_connection *tc;
158 unsigned long flags;
159 struct sockaddr_in sin;
160 int sinlen;
161
162 spin_lock_irqsave(&rds_tcp_tc_list_lock, flags);
163
164 if (len / sizeof(tsinfo) < rds_tcp_tc_count)
165 goto out;
166
167 list_for_each_entry(tc, &rds_tcp_tc_list, t_list_item) {
168
169 sock->ops->getname(sock, (struct sockaddr *)&sin, &sinlen, 0);
170 tsinfo.local_addr = sin.sin_addr.s_addr;
171 tsinfo.local_port = sin.sin_port;
172 sock->ops->getname(sock, (struct sockaddr *)&sin, &sinlen, 1);
173 tsinfo.peer_addr = sin.sin_addr.s_addr;
174 tsinfo.peer_port = sin.sin_port;
175
176 tsinfo.hdr_rem = tc->t_tinc_hdr_rem;
177 tsinfo.data_rem = tc->t_tinc_data_rem;
178 tsinfo.last_sent_nxt = tc->t_last_sent_nxt;
179 tsinfo.last_expected_una = tc->t_last_expected_una;
180 tsinfo.last_seen_una = tc->t_last_seen_una;
181
182 rds_info_copy(iter, &tsinfo, sizeof(tsinfo));
183 }
184
185 out:
186 lens->nr = rds_tcp_tc_count;
187 lens->each = sizeof(tsinfo);
188
189 spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
190 }
191
rds_tcp_laddr_check(__be32 addr)192 static int rds_tcp_laddr_check(__be32 addr)
193 {
194 if (inet_addr_type(&init_net, addr) == RTN_LOCAL)
195 return 0;
196 return -EADDRNOTAVAIL;
197 }
198
rds_tcp_conn_alloc(struct rds_connection * conn,gfp_t gfp)199 static int rds_tcp_conn_alloc(struct rds_connection *conn, gfp_t gfp)
200 {
201 struct rds_tcp_connection *tc;
202
203 tc = kmem_cache_alloc(rds_tcp_conn_slab, gfp);
204 if (!tc)
205 return -ENOMEM;
206
207 tc->t_sock = NULL;
208 tc->t_tinc = NULL;
209 tc->t_tinc_hdr_rem = sizeof(struct rds_header);
210 tc->t_tinc_data_rem = 0;
211
212 conn->c_transport_data = tc;
213
214 spin_lock_irq(&rds_tcp_conn_lock);
215 list_add_tail(&tc->t_tcp_node, &rds_tcp_conn_list);
216 spin_unlock_irq(&rds_tcp_conn_lock);
217
218 rdsdebug("alloced tc %p\n", conn->c_transport_data);
219 return 0;
220 }
221
rds_tcp_conn_free(void * arg)222 static void rds_tcp_conn_free(void *arg)
223 {
224 struct rds_tcp_connection *tc = arg;
225 unsigned long flags;
226 rdsdebug("freeing tc %p\n", tc);
227
228 spin_lock_irqsave(&rds_tcp_conn_lock, flags);
229 list_del(&tc->t_tcp_node);
230 spin_unlock_irqrestore(&rds_tcp_conn_lock, flags);
231
232 kmem_cache_free(rds_tcp_conn_slab, tc);
233 }
234
rds_tcp_destroy_conns(void)235 static void rds_tcp_destroy_conns(void)
236 {
237 struct rds_tcp_connection *tc, *_tc;
238 LIST_HEAD(tmp_list);
239
240 /* avoid calling conn_destroy with irqs off */
241 spin_lock_irq(&rds_tcp_conn_lock);
242 list_splice(&rds_tcp_conn_list, &tmp_list);
243 INIT_LIST_HEAD(&rds_tcp_conn_list);
244 spin_unlock_irq(&rds_tcp_conn_lock);
245
246 list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) {
247 if (tc->conn->c_passive)
248 rds_conn_destroy(tc->conn->c_passive);
249 rds_conn_destroy(tc->conn);
250 }
251 }
252
rds_tcp_exit(void)253 static void rds_tcp_exit(void)
254 {
255 rds_info_deregister_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
256 rds_tcp_listen_stop();
257 rds_tcp_destroy_conns();
258 rds_trans_unregister(&rds_tcp_transport);
259 rds_tcp_recv_exit();
260 kmem_cache_destroy(rds_tcp_conn_slab);
261 }
262 module_exit(rds_tcp_exit);
263
264 struct rds_transport rds_tcp_transport = {
265 .laddr_check = rds_tcp_laddr_check,
266 .xmit_prepare = rds_tcp_xmit_prepare,
267 .xmit_complete = rds_tcp_xmit_complete,
268 .xmit = rds_tcp_xmit,
269 .recv = rds_tcp_recv,
270 .conn_alloc = rds_tcp_conn_alloc,
271 .conn_free = rds_tcp_conn_free,
272 .conn_connect = rds_tcp_conn_connect,
273 .conn_shutdown = rds_tcp_conn_shutdown,
274 .inc_copy_to_user = rds_tcp_inc_copy_to_user,
275 .inc_free = rds_tcp_inc_free,
276 .stats_info_copy = rds_tcp_stats_info_copy,
277 .exit = rds_tcp_exit,
278 .t_owner = THIS_MODULE,
279 .t_name = "tcp",
280 .t_type = RDS_TRANS_TCP,
281 .t_prefer_loopback = 1,
282 };
283
rds_tcp_init(void)284 static int rds_tcp_init(void)
285 {
286 int ret;
287
288 rds_tcp_conn_slab = kmem_cache_create("rds_tcp_connection",
289 sizeof(struct rds_tcp_connection),
290 0, 0, NULL);
291 if (!rds_tcp_conn_slab) {
292 ret = -ENOMEM;
293 goto out;
294 }
295
296 ret = rds_tcp_recv_init();
297 if (ret)
298 goto out_slab;
299
300 ret = rds_trans_register(&rds_tcp_transport);
301 if (ret)
302 goto out_recv;
303
304 ret = rds_tcp_listen_init();
305 if (ret)
306 goto out_register;
307
308 rds_info_register_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
309
310 goto out;
311
312 out_register:
313 rds_trans_unregister(&rds_tcp_transport);
314 out_recv:
315 rds_tcp_recv_exit();
316 out_slab:
317 kmem_cache_destroy(rds_tcp_conn_slab);
318 out:
319 return ret;
320 }
321 module_init(rds_tcp_init);
322
323 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
324 MODULE_DESCRIPTION("RDS: TCP transport");
325 MODULE_LICENSE("Dual BSD/GPL");
326
327