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/uaccess.h> |
24 | #include <linux/fcntl.h> |
25 | #include <linux/mm.h> |
26 | #include <linux/interrupt.h> |
27 | #include <net/netrom.h> |
28 | |
29 | static void nr_heartbeat_expiry(struct timer_list *); |
30 | static void nr_t1timer_expiry(struct timer_list *); |
31 | static void nr_t2timer_expiry(struct timer_list *); |
32 | static void nr_t4timer_expiry(struct timer_list *); |
33 | static void nr_idletimer_expiry(struct timer_list *); |
34 | |
35 | void nr_init_timers(struct sock *sk) |
36 | { |
37 | struct nr_sock *nr = nr_sk(sk); |
38 | |
39 | timer_setup(&nr->t1timer, nr_t1timer_expiry, 0); |
40 | timer_setup(&nr->t2timer, nr_t2timer_expiry, 0); |
41 | timer_setup(&nr->t4timer, nr_t4timer_expiry, 0); |
42 | timer_setup(&nr->idletimer, nr_idletimer_expiry, 0); |
43 | |
44 | /* initialized by sock_init_data */ |
45 | sk->sk_timer.function = nr_heartbeat_expiry; |
46 | } |
47 | |
48 | void nr_start_t1timer(struct sock *sk) |
49 | { |
50 | struct nr_sock *nr = nr_sk(sk); |
51 | |
52 | sk_reset_timer(sk, timer: &nr->t1timer, expires: jiffies + nr->t1); |
53 | } |
54 | |
55 | void nr_start_t2timer(struct sock *sk) |
56 | { |
57 | struct nr_sock *nr = nr_sk(sk); |
58 | |
59 | sk_reset_timer(sk, timer: &nr->t2timer, expires: jiffies + nr->t2); |
60 | } |
61 | |
62 | void nr_start_t4timer(struct sock *sk) |
63 | { |
64 | struct nr_sock *nr = nr_sk(sk); |
65 | |
66 | sk_reset_timer(sk, timer: &nr->t4timer, expires: jiffies + nr->t4); |
67 | } |
68 | |
69 | void nr_start_idletimer(struct sock *sk) |
70 | { |
71 | struct nr_sock *nr = nr_sk(sk); |
72 | |
73 | if (nr->idle > 0) |
74 | sk_reset_timer(sk, timer: &nr->idletimer, expires: jiffies + nr->idle); |
75 | } |
76 | |
77 | void nr_start_heartbeat(struct sock *sk) |
78 | { |
79 | sk_reset_timer(sk, timer: &sk->sk_timer, expires: jiffies + 5 * HZ); |
80 | } |
81 | |
82 | void nr_stop_t1timer(struct sock *sk) |
83 | { |
84 | sk_stop_timer(sk, timer: &nr_sk(sk)->t1timer); |
85 | } |
86 | |
87 | void nr_stop_t2timer(struct sock *sk) |
88 | { |
89 | sk_stop_timer(sk, timer: &nr_sk(sk)->t2timer); |
90 | } |
91 | |
92 | void nr_stop_t4timer(struct sock *sk) |
93 | { |
94 | sk_stop_timer(sk, timer: &nr_sk(sk)->t4timer); |
95 | } |
96 | |
97 | void nr_stop_idletimer(struct sock *sk) |
98 | { |
99 | sk_stop_timer(sk, timer: &nr_sk(sk)->idletimer); |
100 | } |
101 | |
102 | void nr_stop_heartbeat(struct sock *sk) |
103 | { |
104 | sk_stop_timer(sk, timer: &sk->sk_timer); |
105 | } |
106 | |
107 | int nr_t1timer_running(struct sock *sk) |
108 | { |
109 | return timer_pending(timer: &nr_sk(sk)->t1timer); |
110 | } |
111 | |
112 | static void nr_heartbeat_expiry(struct timer_list *t) |
113 | { |
114 | struct sock *sk = from_timer(sk, t, sk_timer); |
115 | struct nr_sock *nr = nr_sk(sk); |
116 | |
117 | bh_lock_sock(sk); |
118 | switch (nr->state) { |
119 | case NR_STATE_0: |
120 | /* Magic here: If we listen() and a new link dies before it |
121 | is accepted() it isn't 'dead' so doesn't get removed. */ |
122 | if (sock_flag(sk, flag: SOCK_DESTROY) || |
123 | (sk->sk_state == TCP_LISTEN && sock_flag(sk, flag: SOCK_DEAD))) { |
124 | sock_hold(sk); |
125 | bh_unlock_sock(sk); |
126 | nr_destroy_socket(sk); |
127 | goto out; |
128 | } |
129 | break; |
130 | |
131 | case NR_STATE_3: |
132 | /* |
133 | * Check for the state of the receive buffer. |
134 | */ |
135 | if (atomic_read(v: &sk->sk_rmem_alloc) < (sk->sk_rcvbuf / 2) && |
136 | (nr->condition & NR_COND_OWN_RX_BUSY)) { |
137 | nr->condition &= ~NR_COND_OWN_RX_BUSY; |
138 | nr->condition &= ~NR_COND_ACK_PENDING; |
139 | nr->vl = nr->vr; |
140 | nr_write_internal(sk, NR_INFOACK); |
141 | break; |
142 | } |
143 | break; |
144 | } |
145 | |
146 | nr_start_heartbeat(sk); |
147 | bh_unlock_sock(sk); |
148 | out: |
149 | sock_put(sk); |
150 | } |
151 | |
152 | static void nr_t2timer_expiry(struct timer_list *t) |
153 | { |
154 | struct nr_sock *nr = from_timer(nr, t, t2timer); |
155 | struct sock *sk = &nr->sock; |
156 | |
157 | bh_lock_sock(sk); |
158 | if (nr->condition & NR_COND_ACK_PENDING) { |
159 | nr->condition &= ~NR_COND_ACK_PENDING; |
160 | nr_enquiry_response(sk); |
161 | } |
162 | bh_unlock_sock(sk); |
163 | sock_put(sk); |
164 | } |
165 | |
166 | static void nr_t4timer_expiry(struct timer_list *t) |
167 | { |
168 | struct nr_sock *nr = from_timer(nr, t, t4timer); |
169 | struct sock *sk = &nr->sock; |
170 | |
171 | bh_lock_sock(sk); |
172 | nr_sk(sk)->condition &= ~NR_COND_PEER_RX_BUSY; |
173 | bh_unlock_sock(sk); |
174 | sock_put(sk); |
175 | } |
176 | |
177 | static void nr_idletimer_expiry(struct timer_list *t) |
178 | { |
179 | struct nr_sock *nr = from_timer(nr, t, idletimer); |
180 | struct sock *sk = &nr->sock; |
181 | |
182 | bh_lock_sock(sk); |
183 | |
184 | nr_clear_queues(sk); |
185 | |
186 | nr->n2count = 0; |
187 | nr_write_internal(sk, NR_DISCREQ); |
188 | nr->state = NR_STATE_2; |
189 | |
190 | nr_start_t1timer(sk); |
191 | nr_stop_t2timer(sk); |
192 | nr_stop_t4timer(sk); |
193 | |
194 | sk->sk_state = TCP_CLOSE; |
195 | sk->sk_err = 0; |
196 | sk->sk_shutdown |= SEND_SHUTDOWN; |
197 | |
198 | if (!sock_flag(sk, flag: SOCK_DEAD)) { |
199 | sk->sk_state_change(sk); |
200 | sock_set_flag(sk, flag: SOCK_DEAD); |
201 | } |
202 | bh_unlock_sock(sk); |
203 | sock_put(sk); |
204 | } |
205 | |
206 | static void nr_t1timer_expiry(struct timer_list *t) |
207 | { |
208 | struct nr_sock *nr = from_timer(nr, t, t1timer); |
209 | struct sock *sk = &nr->sock; |
210 | |
211 | bh_lock_sock(sk); |
212 | switch (nr->state) { |
213 | case NR_STATE_1: |
214 | if (nr->n2count == nr->n2) { |
215 | nr_disconnect(sk, ETIMEDOUT); |
216 | goto out; |
217 | } else { |
218 | nr->n2count++; |
219 | nr_write_internal(sk, NR_CONNREQ); |
220 | } |
221 | break; |
222 | |
223 | case NR_STATE_2: |
224 | if (nr->n2count == nr->n2) { |
225 | nr_disconnect(sk, ETIMEDOUT); |
226 | goto out; |
227 | } else { |
228 | nr->n2count++; |
229 | nr_write_internal(sk, NR_DISCREQ); |
230 | } |
231 | break; |
232 | |
233 | case NR_STATE_3: |
234 | if (nr->n2count == nr->n2) { |
235 | nr_disconnect(sk, ETIMEDOUT); |
236 | goto out; |
237 | } else { |
238 | nr->n2count++; |
239 | nr_requeue_frames(sk); |
240 | } |
241 | break; |
242 | } |
243 | |
244 | nr_start_t1timer(sk); |
245 | out: |
246 | bh_unlock_sock(sk); |
247 | sock_put(sk); |
248 | } |
249 | |