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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/gfp.h>
35#include <linux/in.h>
36#include <net/tcp.h>
37
38#include "rds.h"
39#include "tcp.h"
40
41/*
42 * cheesy, but simple..
43 */
44static void rds_tcp_accept_worker(struct work_struct *work);
45static DECLARE_WORK(rds_tcp_listen_work, rds_tcp_accept_worker);
46static struct socket *rds_tcp_listen_sock;
47
48static int rds_tcp_accept_one(struct socket *sock)
49{
50 struct socket *new_sock = NULL;
51 struct rds_connection *conn;
52 int ret;
53 struct inet_sock *inet;
54
55 ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
56 sock->sk->sk_protocol, &new_sock);
57 if (ret)
58 goto out;
59
60 new_sock->type = sock->type;
61 new_sock->ops = sock->ops;
62 ret = sock->ops->accept(sock, new_sock, O_NONBLOCK);
63 if (ret < 0)
64 goto out;
65
66 rds_tcp_tune(new_sock);
67
68 inet = inet_sk(new_sock->sk);
69
70 rdsdebug("accepted tcp %pI4:%u -> %pI4:%u\n",
71 &inet->inet_saddr, ntohs(inet->inet_sport),
72 &inet->inet_daddr, ntohs(inet->inet_dport));
73
74 conn = rds_conn_create(inet->inet_saddr, inet->inet_daddr,
75 &rds_tcp_transport, GFP_KERNEL);
76 if (IS_ERR(conn)) {
77 ret = PTR_ERR(conn);
78 goto out;
79 }
80
81 /*
82 * see the comment above rds_queue_delayed_reconnect()
83 */
84 if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
85 if (rds_conn_state(conn) == RDS_CONN_UP)
86 rds_tcp_stats_inc(s_tcp_listen_closed_stale);
87 else
88 rds_tcp_stats_inc(s_tcp_connect_raced);
89 rds_conn_drop(conn);
90 ret = 0;
91 goto out;
92 }
93
94 rds_tcp_set_callbacks(new_sock, conn);
95 rds_connect_complete(conn);
96 new_sock = NULL;
97 ret = 0;
98
99out:
100 if (new_sock)
101 sock_release(new_sock);
102 return ret;
103}
104
105static void rds_tcp_accept_worker(struct work_struct *work)
106{
107 while (rds_tcp_accept_one(rds_tcp_listen_sock) == 0)
108 cond_resched();
109}
110
111void rds_tcp_listen_data_ready(struct sock *sk, int bytes)
112{
113 void (*ready)(struct sock *sk, int bytes);
114
115 rdsdebug("listen data ready sk %p\n", sk);
116
117 read_lock_bh(&sk->sk_callback_lock);
118 ready = sk->sk_user_data;
119 if (!ready) { /* check for teardown race */
120 ready = sk->sk_data_ready;
121 goto out;
122 }
123
124 /*
125 * ->sk_data_ready is also called for a newly established child socket
126 * before it has been accepted and the accepter has set up their
127 * data_ready.. we only want to queue listen work for our listening
128 * socket
129 */
130 if (sk->sk_state == TCP_LISTEN)
131 queue_work(rds_wq, &rds_tcp_listen_work);
132
133out:
134 read_unlock_bh(&sk->sk_callback_lock);
135 ready(sk, bytes);
136}
137
138int rds_tcp_listen_init(void)
139{
140 struct sockaddr_in sin;
141 struct socket *sock = NULL;
142 int ret;
143
144 ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
145 if (ret < 0)
146 goto out;
147
148 sock->sk->sk_reuse = SK_CAN_REUSE;
149 rds_tcp_nonagle(sock);
150
151 write_lock_bh(&sock->sk->sk_callback_lock);
152 sock->sk->sk_user_data = sock->sk->sk_data_ready;
153 sock->sk->sk_data_ready = rds_tcp_listen_data_ready;
154 write_unlock_bh(&sock->sk->sk_callback_lock);
155
156 sin.sin_family = PF_INET,
157 sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
158 sin.sin_port = (__force u16)htons(RDS_TCP_PORT);
159
160 ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
161 if (ret < 0)
162 goto out;
163
164 ret = sock->ops->listen(sock, 64);
165 if (ret < 0)
166 goto out;
167
168 rds_tcp_listen_sock = sock;
169 sock = NULL;
170out:
171 if (sock)
172 sock_release(sock);
173 return ret;
174}
175
176void rds_tcp_listen_stop(void)
177{
178 struct socket *sock = rds_tcp_listen_sock;
179 struct sock *sk;
180
181 if (!sock)
182 return;
183
184 sk = sock->sk;
185
186 /* serialize with and prevent further callbacks */
187 lock_sock(sk);
188 write_lock_bh(&sk->sk_callback_lock);
189 if (sk->sk_user_data) {
190 sk->sk_data_ready = sk->sk_user_data;
191 sk->sk_user_data = NULL;
192 }
193 write_unlock_bh(&sk->sk_callback_lock);
194 release_sock(sk);
195
196 /* wait for accepts to stop and close the socket */
197 flush_workqueue(rds_wq);
198 sock_release(sock);
199 rds_tcp_listen_sock = NULL;
200}
1/*
2 * Copyright (c) 2006, 2018 Oracle and/or its affiliates. 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/gfp.h>
35#include <linux/in.h>
36#include <net/tcp.h>
37#include <trace/events/sock.h>
38
39#include "rds.h"
40#include "tcp.h"
41
42void rds_tcp_keepalive(struct socket *sock)
43{
44 /* values below based on xs_udp_default_timeout */
45 int keepidle = 5; /* send a probe 'keepidle' secs after last data */
46 int keepcnt = 5; /* number of unack'ed probes before declaring dead */
47
48 sock_set_keepalive(sock->sk);
49 tcp_sock_set_keepcnt(sock->sk, keepcnt);
50 tcp_sock_set_keepidle(sock->sk, keepidle);
51 /* KEEPINTVL is the interval between successive probes. We follow
52 * the model in xs_tcp_finish_connecting() and re-use keepidle.
53 */
54 tcp_sock_set_keepintvl(sock->sk, keepidle);
55}
56
57/* rds_tcp_accept_one_path(): if accepting on cp_index > 0, make sure the
58 * client's ipaddr < server's ipaddr. Otherwise, close the accepted
59 * socket and force a reconneect from smaller -> larger ip addr. The reason
60 * we special case cp_index 0 is to allow the rds probe ping itself to itself
61 * get through efficiently.
62 * Since reconnects are only initiated from the node with the numerically
63 * smaller ip address, we recycle conns in RDS_CONN_ERROR on the passive side
64 * by moving them to CONNECTING in this function.
65 */
66static
67struct rds_tcp_connection *rds_tcp_accept_one_path(struct rds_connection *conn)
68{
69 int i;
70 int npaths = max_t(int, 1, conn->c_npaths);
71
72 /* for mprds, all paths MUST be initiated by the peer
73 * with the smaller address.
74 */
75 if (rds_addr_cmp(&conn->c_faddr, &conn->c_laddr) >= 0) {
76 /* Make sure we initiate at least one path if this
77 * has not already been done; rds_start_mprds() will
78 * take care of additional paths, if necessary.
79 */
80 if (npaths == 1)
81 rds_conn_path_connect_if_down(&conn->c_path[0]);
82 return NULL;
83 }
84
85 for (i = 0; i < npaths; i++) {
86 struct rds_conn_path *cp = &conn->c_path[i];
87
88 if (rds_conn_path_transition(cp, RDS_CONN_DOWN,
89 RDS_CONN_CONNECTING) ||
90 rds_conn_path_transition(cp, RDS_CONN_ERROR,
91 RDS_CONN_CONNECTING)) {
92 return cp->cp_transport_data;
93 }
94 }
95 return NULL;
96}
97
98int rds_tcp_accept_one(struct socket *sock)
99{
100 struct socket *new_sock = NULL;
101 struct rds_connection *conn;
102 int ret;
103 struct inet_sock *inet;
104 struct rds_tcp_connection *rs_tcp = NULL;
105 int conn_state;
106 struct rds_conn_path *cp;
107 struct in6_addr *my_addr, *peer_addr;
108#if !IS_ENABLED(CONFIG_IPV6)
109 struct in6_addr saddr, daddr;
110#endif
111 int dev_if = 0;
112
113 if (!sock) /* module unload or netns delete in progress */
114 return -ENETUNREACH;
115
116 ret = sock_create_lite(sock->sk->sk_family,
117 sock->sk->sk_type, sock->sk->sk_protocol,
118 &new_sock);
119 if (ret)
120 goto out;
121
122 ret = sock->ops->accept(sock, new_sock, O_NONBLOCK, true);
123 if (ret < 0)
124 goto out;
125
126 /* sock_create_lite() does not get a hold on the owner module so we
127 * need to do it here. Note that sock_release() uses sock->ops to
128 * determine if it needs to decrement the reference count. So set
129 * sock->ops after calling accept() in case that fails. And there's
130 * no need to do try_module_get() as the listener should have a hold
131 * already.
132 */
133 new_sock->ops = sock->ops;
134 __module_get(new_sock->ops->owner);
135
136 rds_tcp_keepalive(new_sock);
137 if (!rds_tcp_tune(new_sock)) {
138 ret = -EINVAL;
139 goto out;
140 }
141
142 inet = inet_sk(new_sock->sk);
143
144#if IS_ENABLED(CONFIG_IPV6)
145 my_addr = &new_sock->sk->sk_v6_rcv_saddr;
146 peer_addr = &new_sock->sk->sk_v6_daddr;
147#else
148 ipv6_addr_set_v4mapped(inet->inet_saddr, &saddr);
149 ipv6_addr_set_v4mapped(inet->inet_daddr, &daddr);
150 my_addr = &saddr;
151 peer_addr = &daddr;
152#endif
153 rdsdebug("accepted family %d tcp %pI6c:%u -> %pI6c:%u\n",
154 sock->sk->sk_family,
155 my_addr, ntohs(inet->inet_sport),
156 peer_addr, ntohs(inet->inet_dport));
157
158#if IS_ENABLED(CONFIG_IPV6)
159 /* sk_bound_dev_if is not set if the peer address is not link local
160 * address. In this case, it happens that mcast_oif is set. So
161 * just use it.
162 */
163 if ((ipv6_addr_type(my_addr) & IPV6_ADDR_LINKLOCAL) &&
164 !(ipv6_addr_type(peer_addr) & IPV6_ADDR_LINKLOCAL)) {
165 struct ipv6_pinfo *inet6;
166
167 inet6 = inet6_sk(new_sock->sk);
168 dev_if = READ_ONCE(inet6->mcast_oif);
169 } else {
170 dev_if = new_sock->sk->sk_bound_dev_if;
171 }
172#endif
173
174 if (!rds_tcp_laddr_check(sock_net(sock->sk), peer_addr, dev_if)) {
175 /* local address connection is only allowed via loopback */
176 ret = -EOPNOTSUPP;
177 goto out;
178 }
179
180 conn = rds_conn_create(sock_net(sock->sk),
181 my_addr, peer_addr,
182 &rds_tcp_transport, 0, GFP_KERNEL, dev_if);
183
184 if (IS_ERR(conn)) {
185 ret = PTR_ERR(conn);
186 goto out;
187 }
188 /* An incoming SYN request came in, and TCP just accepted it.
189 *
190 * If the client reboots, this conn will need to be cleaned up.
191 * rds_tcp_state_change() will do that cleanup
192 */
193 rs_tcp = rds_tcp_accept_one_path(conn);
194 if (!rs_tcp)
195 goto rst_nsk;
196 mutex_lock(&rs_tcp->t_conn_path_lock);
197 cp = rs_tcp->t_cpath;
198 conn_state = rds_conn_path_state(cp);
199 WARN_ON(conn_state == RDS_CONN_UP);
200 if (conn_state != RDS_CONN_CONNECTING && conn_state != RDS_CONN_ERROR)
201 goto rst_nsk;
202 if (rs_tcp->t_sock) {
203 /* Duelling SYN has been handled in rds_tcp_accept_one() */
204 rds_tcp_reset_callbacks(new_sock, cp);
205 /* rds_connect_path_complete() marks RDS_CONN_UP */
206 rds_connect_path_complete(cp, RDS_CONN_RESETTING);
207 } else {
208 rds_tcp_set_callbacks(new_sock, cp);
209 rds_connect_path_complete(cp, RDS_CONN_CONNECTING);
210 }
211 new_sock = NULL;
212 ret = 0;
213 if (conn->c_npaths == 0)
214 rds_send_ping(cp->cp_conn, cp->cp_index);
215 goto out;
216rst_nsk:
217 /* reset the newly returned accept sock and bail.
218 * It is safe to set linger on new_sock because the RDS connection
219 * has not been brought up on new_sock, so no RDS-level data could
220 * be pending on it. By setting linger, we achieve the side-effect
221 * of avoiding TIME_WAIT state on new_sock.
222 */
223 sock_no_linger(new_sock->sk);
224 kernel_sock_shutdown(new_sock, SHUT_RDWR);
225 ret = 0;
226out:
227 if (rs_tcp)
228 mutex_unlock(&rs_tcp->t_conn_path_lock);
229 if (new_sock)
230 sock_release(new_sock);
231 return ret;
232}
233
234void rds_tcp_listen_data_ready(struct sock *sk)
235{
236 void (*ready)(struct sock *sk);
237
238 trace_sk_data_ready(sk);
239 rdsdebug("listen data ready sk %p\n", sk);
240
241 read_lock_bh(&sk->sk_callback_lock);
242 ready = sk->sk_user_data;
243 if (!ready) { /* check for teardown race */
244 ready = sk->sk_data_ready;
245 goto out;
246 }
247
248 /*
249 * ->sk_data_ready is also called for a newly established child socket
250 * before it has been accepted and the accepter has set up their
251 * data_ready.. we only want to queue listen work for our listening
252 * socket
253 *
254 * (*ready)() may be null if we are racing with netns delete, and
255 * the listen socket is being torn down.
256 */
257 if (sk->sk_state == TCP_LISTEN)
258 rds_tcp_accept_work(sk);
259 else
260 ready = rds_tcp_listen_sock_def_readable(sock_net(sk));
261
262out:
263 read_unlock_bh(&sk->sk_callback_lock);
264 if (ready)
265 ready(sk);
266}
267
268struct socket *rds_tcp_listen_init(struct net *net, bool isv6)
269{
270 struct socket *sock = NULL;
271 struct sockaddr_storage ss;
272 struct sockaddr_in6 *sin6;
273 struct sockaddr_in *sin;
274 int addr_len;
275 int ret;
276
277 ret = sock_create_kern(net, isv6 ? PF_INET6 : PF_INET, SOCK_STREAM,
278 IPPROTO_TCP, &sock);
279 if (ret < 0) {
280 rdsdebug("could not create %s listener socket: %d\n",
281 isv6 ? "IPv6" : "IPv4", ret);
282 goto out;
283 }
284
285 sock->sk->sk_reuse = SK_CAN_REUSE;
286 tcp_sock_set_nodelay(sock->sk);
287
288 write_lock_bh(&sock->sk->sk_callback_lock);
289 sock->sk->sk_user_data = sock->sk->sk_data_ready;
290 sock->sk->sk_data_ready = rds_tcp_listen_data_ready;
291 write_unlock_bh(&sock->sk->sk_callback_lock);
292
293 if (isv6) {
294 sin6 = (struct sockaddr_in6 *)&ss;
295 sin6->sin6_family = PF_INET6;
296 sin6->sin6_addr = in6addr_any;
297 sin6->sin6_port = (__force u16)htons(RDS_TCP_PORT);
298 sin6->sin6_scope_id = 0;
299 sin6->sin6_flowinfo = 0;
300 addr_len = sizeof(*sin6);
301 } else {
302 sin = (struct sockaddr_in *)&ss;
303 sin->sin_family = PF_INET;
304 sin->sin_addr.s_addr = INADDR_ANY;
305 sin->sin_port = (__force u16)htons(RDS_TCP_PORT);
306 addr_len = sizeof(*sin);
307 }
308
309 ret = kernel_bind(sock, (struct sockaddr *)&ss, addr_len);
310 if (ret < 0) {
311 rdsdebug("could not bind %s listener socket: %d\n",
312 isv6 ? "IPv6" : "IPv4", ret);
313 goto out;
314 }
315
316 ret = sock->ops->listen(sock, 64);
317 if (ret < 0)
318 goto out;
319
320 return sock;
321out:
322 if (sock)
323 sock_release(sock);
324 return NULL;
325}
326
327void rds_tcp_listen_stop(struct socket *sock, struct work_struct *acceptor)
328{
329 struct sock *sk;
330
331 if (!sock)
332 return;
333
334 sk = sock->sk;
335
336 /* serialize with and prevent further callbacks */
337 lock_sock(sk);
338 write_lock_bh(&sk->sk_callback_lock);
339 if (sk->sk_user_data) {
340 sk->sk_data_ready = sk->sk_user_data;
341 sk->sk_user_data = NULL;
342 }
343 write_unlock_bh(&sk->sk_callback_lock);
344 release_sock(sk);
345
346 /* wait for accepts to stop and close the socket */
347 flush_workqueue(rds_wq);
348 flush_work(acceptor);
349 sock_release(sock);
350}