Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 | // SPDX-License-Identifier: GPL-2.0-or-later /* * X.25 Packet Layer release 002 * * This is ALPHA test software. This code may break your machine, * randomly fail to work with new releases, misbehave and/or generally * screw up. It might even work. * * This code REQUIRES 2.1.15 or higher * * History * X.25 001 Jonathan Naylor Started coding. * X.25 002 Jonathan Naylor New timer architecture. * Centralised disconnection processing. */ #include <linux/errno.h> #include <linux/jiffies.h> #include <linux/timer.h> #include <net/sock.h> #include <net/tcp_states.h> #include <net/x25.h> static void x25_heartbeat_expiry(struct timer_list *t); static void x25_timer_expiry(struct timer_list *t); void x25_init_timers(struct sock *sk) { struct x25_sock *x25 = x25_sk(sk); timer_setup(&x25->timer, x25_timer_expiry, 0); /* initialized by sock_init_data */ sk->sk_timer.function = x25_heartbeat_expiry; } void x25_start_heartbeat(struct sock *sk) { mod_timer(&sk->sk_timer, jiffies + 5 * HZ); } void x25_stop_heartbeat(struct sock *sk) { del_timer(&sk->sk_timer); } void x25_start_t2timer(struct sock *sk) { struct x25_sock *x25 = x25_sk(sk); mod_timer(&x25->timer, jiffies + x25->t2); } void x25_start_t21timer(struct sock *sk) { struct x25_sock *x25 = x25_sk(sk); mod_timer(&x25->timer, jiffies + x25->t21); } void x25_start_t22timer(struct sock *sk) { struct x25_sock *x25 = x25_sk(sk); mod_timer(&x25->timer, jiffies + x25->t22); } void x25_start_t23timer(struct sock *sk) { struct x25_sock *x25 = x25_sk(sk); mod_timer(&x25->timer, jiffies + x25->t23); } void x25_stop_timer(struct sock *sk) { del_timer(&x25_sk(sk)->timer); } unsigned long x25_display_timer(struct sock *sk) { struct x25_sock *x25 = x25_sk(sk); if (!timer_pending(&x25->timer)) return 0; return x25->timer.expires - jiffies; } static void x25_heartbeat_expiry(struct timer_list *t) { struct sock *sk = from_timer(sk, t, sk_timer); bh_lock_sock(sk); if (sock_owned_by_user(sk)) /* can currently only occur in state 3 */ goto restart_heartbeat; switch (x25_sk(sk)->state) { case X25_STATE_0: /* * Magic here: If we listen() and a new link dies * before it is accepted() it isn't 'dead' so doesn't * get removed. */ if (sock_flag(sk, SOCK_DESTROY) || (sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_DEAD))) { bh_unlock_sock(sk); x25_destroy_socket_from_timer(sk); return; } break; case X25_STATE_3: /* * Check for the state of the receive buffer. */ x25_check_rbuf(sk); break; } restart_heartbeat: x25_start_heartbeat(sk); bh_unlock_sock(sk); } /* * Timer has expired, it may have been T2, T21, T22, or T23. We can tell * by the state machine state. */ static inline void x25_do_timer_expiry(struct sock * sk) { struct x25_sock *x25 = x25_sk(sk); switch (x25->state) { case X25_STATE_3: /* T2 */ if (x25->condition & X25_COND_ACK_PENDING) { x25->condition &= ~X25_COND_ACK_PENDING; x25_enquiry_response(sk); } break; case X25_STATE_1: /* T21 */ case X25_STATE_4: /* T22 */ x25_write_internal(sk, X25_CLEAR_REQUEST); x25->state = X25_STATE_2; x25_start_t23timer(sk); break; case X25_STATE_2: /* T23 */ x25_disconnect(sk, ETIMEDOUT, 0, 0); break; } } static void x25_timer_expiry(struct timer_list *t) { struct x25_sock *x25 = from_timer(x25, t, timer); struct sock *sk = &x25->sk; bh_lock_sock(sk); if (sock_owned_by_user(sk)) { /* can currently only occur in state 3 */ if (x25_sk(sk)->state == X25_STATE_3) x25_start_t2timer(sk); } else x25_do_timer_expiry(sk); bh_unlock_sock(sk); } |