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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 | int rds_tcp_keepalive(struct socket *sock) | |
42 | { | |
43 | /* values below based on xs_udp_default_timeout */ | |
44 | int keepidle = 5; /* send a probe 'keepidle' secs after last data */ | |
45 | int keepcnt = 5; /* number of unack'ed probes before declaring dead */ | |
46 | int keepalive = 1; | |
47 | int ret = 0; | |
48 | ||
49 | ret = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, | |
50 | (char *)&keepalive, sizeof(keepalive)); | |
51 | if (ret < 0) | |
52 | goto bail; | |
53 | ||
54 | ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPCNT, | |
55 | (char *)&keepcnt, sizeof(keepcnt)); | |
56 | if (ret < 0) | |
57 | goto bail; | |
58 | ||
59 | ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPIDLE, | |
60 | (char *)&keepidle, sizeof(keepidle)); | |
61 | if (ret < 0) | |
62 | goto bail; | |
63 | ||
64 | /* KEEPINTVL is the interval between successive probes. We follow | |
65 | * the model in xs_tcp_finish_connecting() and re-use keepidle. | |
66 | */ | |
67 | ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPINTVL, | |
68 | (char *)&keepidle, sizeof(keepidle)); | |
69 | bail: | |
70 | return ret; | |
71 | } | |
72 | ||
73 | /* rds_tcp_accept_one_path(): if accepting on cp_index > 0, make sure the | |
74 | * client's ipaddr < server's ipaddr. Otherwise, close the accepted | |
75 | * socket and force a reconneect from smaller -> larger ip addr. The reason | |
76 | * we special case cp_index 0 is to allow the rds probe ping itself to itself | |
77 | * get through efficiently. | |
78 | * Since reconnects are only initiated from the node with the numerically | |
79 | * smaller ip address, we recycle conns in RDS_CONN_ERROR on the passive side | |
80 | * by moving them to CONNECTING in this function. | |
81 | */ | |
82 | struct rds_tcp_connection *rds_tcp_accept_one_path(struct rds_connection *conn) | |
83 | { | |
84 | int i; | |
85 | bool peer_is_smaller = (conn->c_faddr < conn->c_laddr); | |
86 | int npaths = conn->c_npaths; | |
87 | ||
88 | if (npaths <= 1) { | |
89 | struct rds_conn_path *cp = &conn->c_path[0]; | |
90 | int ret; | |
91 | ||
92 | ret = rds_conn_path_transition(cp, RDS_CONN_DOWN, | |
93 | RDS_CONN_CONNECTING); | |
94 | if (!ret) | |
95 | rds_conn_path_transition(cp, RDS_CONN_ERROR, | |
96 | RDS_CONN_CONNECTING); | |
97 | return cp->cp_transport_data; | |
98 | } | |
99 | ||
100 | /* for mprds, paths with cp_index > 0 MUST be initiated by the peer | |
101 | * with the smaller address. | |
102 | */ | |
103 | if (!peer_is_smaller) | |
104 | return NULL; | |
105 | ||
106 | for (i = 1; i < npaths; i++) { | |
107 | struct rds_conn_path *cp = &conn->c_path[i]; | |
108 | ||
109 | if (rds_conn_path_transition(cp, RDS_CONN_DOWN, | |
110 | RDS_CONN_CONNECTING) || | |
111 | rds_conn_path_transition(cp, RDS_CONN_ERROR, | |
112 | RDS_CONN_CONNECTING)) { | |
113 | return cp->cp_transport_data; | |
114 | } | |
115 | } | |
116 | return NULL; | |
117 | } | |
118 | ||
119 | int rds_tcp_accept_one(struct socket *sock) | |
120 | { | |
121 | struct socket *new_sock = NULL; | |
122 | struct rds_connection *conn; | |
123 | int ret; | |
124 | struct inet_sock *inet; | |
125 | struct rds_tcp_connection *rs_tcp = NULL; | |
126 | int conn_state; | |
127 | struct rds_conn_path *cp; | |
128 | ||
129 | if (!sock) /* module unload or netns delete in progress */ | |
130 | return -ENETUNREACH; | |
131 | ||
132 | ret = sock_create_kern(sock_net(sock->sk), sock->sk->sk_family, | |
133 | sock->sk->sk_type, sock->sk->sk_protocol, | |
134 | &new_sock); | |
135 | if (ret) | |
136 | goto out; | |
137 | ||
138 | new_sock->type = sock->type; | |
139 | new_sock->ops = sock->ops; | |
140 | ret = sock->ops->accept(sock, new_sock, O_NONBLOCK); | |
141 | if (ret < 0) | |
142 | goto out; | |
143 | ||
144 | ret = rds_tcp_keepalive(new_sock); | |
145 | if (ret < 0) | |
146 | goto out; | |
147 | ||
148 | rds_tcp_tune(new_sock); | |
149 | ||
150 | inet = inet_sk(new_sock->sk); | |
151 | ||
152 | rdsdebug("accepted tcp %pI4:%u -> %pI4:%u\n", | |
153 | &inet->inet_saddr, ntohs(inet->inet_sport), | |
154 | &inet->inet_daddr, ntohs(inet->inet_dport)); | |
155 | ||
156 | conn = rds_conn_create(sock_net(sock->sk), | |
157 | inet->inet_saddr, inet->inet_daddr, | |
158 | &rds_tcp_transport, GFP_KERNEL); | |
159 | if (IS_ERR(conn)) { | |
160 | ret = PTR_ERR(conn); | |
161 | goto out; | |
162 | } | |
163 | /* An incoming SYN request came in, and TCP just accepted it. | |
164 | * | |
165 | * If the client reboots, this conn will need to be cleaned up. | |
166 | * rds_tcp_state_change() will do that cleanup | |
167 | */ | |
168 | rs_tcp = rds_tcp_accept_one_path(conn); | |
169 | if (!rs_tcp) | |
170 | goto rst_nsk; | |
171 | mutex_lock(&rs_tcp->t_conn_path_lock); | |
172 | cp = rs_tcp->t_cpath; | |
173 | conn_state = rds_conn_path_state(cp); | |
174 | if (conn_state != RDS_CONN_CONNECTING && conn_state != RDS_CONN_UP && | |
175 | conn_state != RDS_CONN_ERROR) | |
176 | goto rst_nsk; | |
177 | if (rs_tcp->t_sock) { | |
178 | /* Need to resolve a duelling SYN between peers. | |
179 | * We have an outstanding SYN to this peer, which may | |
180 | * potentially have transitioned to the RDS_CONN_UP state, | |
181 | * so we must quiesce any send threads before resetting | |
182 | * c_transport_data. | |
183 | */ | |
184 | if (ntohl(inet->inet_saddr) < ntohl(inet->inet_daddr) || | |
185 | !cp->cp_outgoing) { | |
186 | goto rst_nsk; | |
187 | } else { | |
188 | rds_tcp_reset_callbacks(new_sock, cp); | |
189 | cp->cp_outgoing = 0; | |
190 | /* rds_connect_path_complete() marks RDS_CONN_UP */ | |
191 | rds_connect_path_complete(cp, RDS_CONN_RESETTING); | |
192 | } | |
193 | } else { | |
194 | rds_tcp_set_callbacks(new_sock, cp); | |
195 | rds_connect_path_complete(cp, RDS_CONN_CONNECTING); | |
196 | } | |
197 | new_sock = NULL; | |
198 | ret = 0; | |
199 | goto out; | |
200 | rst_nsk: | |
201 | /* reset the newly returned accept sock and bail */ | |
202 | kernel_sock_shutdown(new_sock, SHUT_RDWR); | |
203 | ret = 0; | |
204 | out: | |
205 | if (rs_tcp) | |
206 | mutex_unlock(&rs_tcp->t_conn_path_lock); | |
207 | if (new_sock) | |
208 | sock_release(new_sock); | |
209 | return ret; | |
210 | } | |
211 | ||
212 | void rds_tcp_listen_data_ready(struct sock *sk) | |
213 | { | |
214 | void (*ready)(struct sock *sk); | |
215 | ||
216 | rdsdebug("listen data ready sk %p\n", sk); | |
217 | ||
218 | read_lock_bh(&sk->sk_callback_lock); | |
219 | ready = sk->sk_user_data; | |
220 | if (!ready) { /* check for teardown race */ | |
221 | ready = sk->sk_data_ready; | |
222 | goto out; | |
223 | } | |
224 | ||
225 | /* | |
226 | * ->sk_data_ready is also called for a newly established child socket | |
227 | * before it has been accepted and the accepter has set up their | |
228 | * data_ready.. we only want to queue listen work for our listening | |
229 | * socket | |
230 | */ | |
231 | if (sk->sk_state == TCP_LISTEN) | |
232 | rds_tcp_accept_work(sk); | |
233 | else | |
234 | ready = rds_tcp_listen_sock_def_readable(sock_net(sk)); | |
235 | ||
236 | out: | |
237 | read_unlock_bh(&sk->sk_callback_lock); | |
238 | ready(sk); | |
239 | } | |
240 | ||
241 | struct socket *rds_tcp_listen_init(struct net *net) | |
242 | { | |
243 | struct sockaddr_in sin; | |
244 | struct socket *sock = NULL; | |
245 | int ret; | |
246 | ||
247 | ret = sock_create_kern(net, PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock); | |
248 | if (ret < 0) | |
249 | goto out; | |
250 | ||
251 | sock->sk->sk_reuse = SK_CAN_REUSE; | |
252 | rds_tcp_nonagle(sock); | |
253 | ||
254 | write_lock_bh(&sock->sk->sk_callback_lock); | |
255 | sock->sk->sk_user_data = sock->sk->sk_data_ready; | |
256 | sock->sk->sk_data_ready = rds_tcp_listen_data_ready; | |
257 | write_unlock_bh(&sock->sk->sk_callback_lock); | |
258 | ||
259 | sin.sin_family = PF_INET; | |
260 | sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY); | |
261 | sin.sin_port = (__force u16)htons(RDS_TCP_PORT); | |
262 | ||
263 | ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin)); | |
264 | if (ret < 0) | |
265 | goto out; | |
266 | ||
267 | ret = sock->ops->listen(sock, 64); | |
268 | if (ret < 0) | |
269 | goto out; | |
270 | ||
271 | return sock; | |
272 | out: | |
273 | if (sock) | |
274 | sock_release(sock); | |
275 | return NULL; | |
276 | } | |
277 | ||
278 | void rds_tcp_listen_stop(struct socket *sock) | |
279 | { | |
280 | struct sock *sk; | |
281 | ||
282 | if (!sock) | |
283 | return; | |
284 | ||
285 | sk = sock->sk; | |
286 | ||
287 | /* serialize with and prevent further callbacks */ | |
288 | lock_sock(sk); | |
289 | write_lock_bh(&sk->sk_callback_lock); | |
290 | if (sk->sk_user_data) { | |
291 | sk->sk_data_ready = sk->sk_user_data; | |
292 | sk->sk_user_data = NULL; | |
293 | } | |
294 | write_unlock_bh(&sk->sk_callback_lock); | |
295 | release_sock(sk); | |
296 | ||
297 | /* wait for accepts to stop and close the socket */ | |
298 | flush_workqueue(rds_wq); | |
299 | sock_release(sock); | |
300 | } |