Root/net/rds/tcp.c

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

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