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tcp.c
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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 #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() */
57 {
58  mm_segment_t oldfs = get_fs();
59  int val = 1;
60 
62  sock->ops->setsockopt(sock, SOL_TCP, TCP_NODELAY, (char __user *)&val,
63  sizeof(val));
64  set_fs(oldfs);
65 }
66 
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);
81  release_sock(sk);
82 }
83 
85 {
86  return tcp_sk(tc->t_sock->sk)->snd_nxt;
87 }
88 
90 {
91  return tcp_sk(tc->t_sock->sk)->snd_una;
92 }
93 
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  */
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 
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 
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 
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 
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 
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 
253 static void rds_tcp_exit(void)
254 {
257  rds_tcp_destroy_conns();
260  kmem_cache_destroy(rds_tcp_conn_slab);
261 }
262 module_exit(rds_tcp_exit);
263 
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 
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 
309 
310  goto out;
311 
312 out_register:
313  rds_trans_unregister(&rds_tcp_transport);
314 out_recv:
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 <[email protected]>");
324 MODULE_DESCRIPTION("RDS: TCP transport");
325 MODULE_LICENSE("Dual BSD/GPL");
326