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