1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 *
4 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
5 * Copyright (C) 2002 Ralf Baechle DO1GRB (ralf@gnu.org)
6 */
7 #include <linux/errno.h>
8 #include <linux/types.h>
9 #include <linux/socket.h>
10 #include <linux/in.h>
11 #include <linux/kernel.h>
12 #include <linux/jiffies.h>
13 #include <linux/timer.h>
14 #include <linux/string.h>
15 #include <linux/sockios.h>
16 #include <linux/net.h>
17 #include <net/ax25.h>
18 #include <linux/inet.h>
19 #include <linux/netdevice.h>
20 #include <linux/skbuff.h>
21 #include <net/sock.h>
22 #include <net/tcp_states.h>
23 #include <linux/fcntl.h>
24 #include <linux/mm.h>
25 #include <linux/interrupt.h>
26 #include <net/rose.h>
27
28 static void rose_heartbeat_expiry(struct timer_list *t);
29 static void rose_timer_expiry(struct timer_list *);
30 static void rose_idletimer_expiry(struct timer_list *);
31
32 void rose_start_heartbeat(struct sock *sk)
33 {
34 sk_stop_timer(sk, &sk->sk_timer);
35
36 sk->sk_timer.function = rose_heartbeat_expiry;
37 sk->sk_timer.expires = jiffies + 5 * HZ;
38
39 sk_reset_timer(sk, &sk->sk_timer, sk->sk_timer.expires);
40 }
41
42 void rose_start_t1timer(struct sock *sk)
43 {
44 struct rose_sock *rose = rose_sk(sk);
45
46 sk_stop_timer(sk, &rose->timer);
47
48 rose->timer.function = rose_timer_expiry;
49 rose->timer.expires = jiffies + rose->t1;
50
51 sk_reset_timer(sk, &rose->timer, rose->timer.expires);
52 }
53
54 void rose_start_t2timer(struct sock *sk)
55 {
56 struct rose_sock *rose = rose_sk(sk);
57
58 sk_stop_timer(sk, &rose->timer);
59
60 rose->timer.function = rose_timer_expiry;
61 rose->timer.expires = jiffies + rose->t2;
62
63 sk_reset_timer(sk, &rose->timer, rose->timer.expires);
64 }
65
66 void rose_start_t3timer(struct sock *sk)
67 {
68 struct rose_sock *rose = rose_sk(sk);
69
70 sk_stop_timer(sk, &rose->timer);
71
72 rose->timer.function = rose_timer_expiry;
73 rose->timer.expires = jiffies + rose->t3;
74
75 sk_reset_timer(sk, &rose->timer, rose->timer.expires);
76 }
77
78 void rose_start_hbtimer(struct sock *sk)
79 {
80 struct rose_sock *rose = rose_sk(sk);
81
82 sk_stop_timer(sk, &rose->timer);
83
84 rose->timer.function = rose_timer_expiry;
85 rose->timer.expires = jiffies + rose->hb;
86
87 sk_reset_timer(sk, &rose->timer, rose->timer.expires);
88 }
89
90 void rose_start_idletimer(struct sock *sk)
91 {
92 struct rose_sock *rose = rose_sk(sk);
93
94 sk_stop_timer(sk, &rose->idletimer);
95
96 if (rose->idle > 0) {
97 rose->idletimer.function = rose_idletimer_expiry;
98 rose->idletimer.expires = jiffies + rose->idle;
99
100 sk_reset_timer(sk, &rose->idletimer, rose->idletimer.expires);
101 }
102 }
103
104 void rose_stop_heartbeat(struct sock *sk)
105 {
106 sk_stop_timer(sk, &sk->sk_timer);
107 }
108
109 void rose_stop_timer(struct sock *sk)
110 {
111 sk_stop_timer(sk, &rose_sk(sk)->timer);
112 }
113
114 void rose_stop_idletimer(struct sock *sk)
115 {
116 sk_stop_timer(sk, &rose_sk(sk)->idletimer);
117 }
118
119 static void rose_heartbeat_expiry(struct timer_list *t)
120 {
121 struct sock *sk = from_timer(sk, t, sk_timer);
122 struct rose_sock *rose = rose_sk(sk);
123
124 bh_lock_sock(sk);
125 switch (rose->state) {
126 case ROSE_STATE_0:
127 /* Magic here: If we listen() and a new link dies before it
128 is accepted() it isn't 'dead' so doesn't get removed. */
129 if (sock_flag(sk, SOCK_DESTROY) ||
130 (sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_DEAD))) {
131 bh_unlock_sock(sk);
132 rose_destroy_socket(sk);
133 sock_put(sk);
134 return;
135 }
136 break;
137
138 case ROSE_STATE_3:
139 /*
140 * Check for the state of the receive buffer.
141 */
142 if (atomic_read(&sk->sk_rmem_alloc) < (sk->sk_rcvbuf / 2) &&
143 (rose->condition & ROSE_COND_OWN_RX_BUSY)) {
144 rose->condition &= ~ROSE_COND_OWN_RX_BUSY;
145 rose->condition &= ~ROSE_COND_ACK_PENDING;
146 rose->vl = rose->vr;
147 rose_write_internal(sk, ROSE_RR);
148 rose_stop_timer(sk); /* HB */
149 break;
150 }
151 break;
152 }
153
154 rose_start_heartbeat(sk);
155 bh_unlock_sock(sk);
156 sock_put(sk);
157 }
158
159 static void rose_timer_expiry(struct timer_list *t)
160 {
161 struct rose_sock *rose = from_timer(rose, t, timer);
162 struct sock *sk = &rose->sock;
163
164 bh_lock_sock(sk);
165 switch (rose->state) {
166 case ROSE_STATE_1: /* T1 */
167 case ROSE_STATE_4: /* T2 */
168 rose_write_internal(sk, ROSE_CLEAR_REQUEST);
169 rose->state = ROSE_STATE_2;
170 rose_start_t3timer(sk);
171 break;
172
173 case ROSE_STATE_2: /* T3 */
174 rose->neighbour->use--;
175 rose_disconnect(sk, ETIMEDOUT, -1, -1);
176 break;
177
178 case ROSE_STATE_3: /* HB */
179 if (rose->condition & ROSE_COND_ACK_PENDING) {
180 rose->condition &= ~ROSE_COND_ACK_PENDING;
181 rose_enquiry_response(sk);
182 }
183 break;
184 }
185 bh_unlock_sock(sk);
186 sock_put(sk);
187 }
188
189 static void rose_idletimer_expiry(struct timer_list *t)
190 {
191 struct rose_sock *rose = from_timer(rose, t, idletimer);
192 struct sock *sk = &rose->sock;
193
194 bh_lock_sock(sk);
195 rose_clear_queues(sk);
196
197 rose_write_internal(sk, ROSE_CLEAR_REQUEST);
198 rose_sk(sk)->state = ROSE_STATE_2;
199
200 rose_start_t3timer(sk);
201
202 sk->sk_state = TCP_CLOSE;
203 sk->sk_err = 0;
204 sk->sk_shutdown |= SEND_SHUTDOWN;
205
206 if (!sock_flag(sk, SOCK_DEAD)) {
207 sk->sk_state_change(sk);
208 sock_set_flag(sk, SOCK_DEAD);
209 }
210 bh_unlock_sock(sk);
211 sock_put(sk);
212 }
213
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