/* * State machine for state 4, Awaiting Reset Confirmation State. * The handling of the timer(s) is in file x25_timer.c * Handling of state 0 and connection release is in af_x25.c. */ static int x25_state4_machine(struct sock *sk, struct sk_buff *skb, int frametype) { switch (frametype) { case X25_RESET_REQUEST: x25_write_internal(sk, X25_RESET_CONFIRMATION); case X25_RESET_CONFIRMATION: { struct x25_sock *x25 = x25_sk(sk); x25_stop_timer(sk); x25->condition = 0x00; x25->va = 0; x25->vr = 0; x25->vs = 0; x25->vl = 0; x25->state = X25_STATE_3; x25_requeue_frames(sk); break; } case X25_CLEAR_REQUEST: x25_write_internal(sk, X25_CLEAR_CONFIRMATION); x25_disconnect(sk, 0, skb->data[3], skb->data[4]); break; default: break; } return 0; }
/* * 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_opt *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; } }
int x25_clear_request(struct x25_cs * x25) { if (!x25) return 0; struct x25_cs_internal * x25_int = x25_get_internal(x25); switch (x25_int->state) { case X25_STATE_0: case X25_STATE_2: x25_disconnect(x25, 0, 0, 0); break; case X25_STATE_1: case X25_STATE_3: case X25_STATE_4: x25_clear_queues(x25); x25->callbacks->debug(2, "[X25] S%d TX CLEAR_REQUEST", x25_int->state); _uchar old_state = x25_int->state; x25_int->state = X25_STATE_2; x25_write_internal(x25, X25_CLEAR_REQUEST); x25_start_timer(x25, &x25_int->ClearTimer); x25->callbacks->debug(1, "[X25] S%d -> S2", old_state); break; }; return 0; }
/* * State machine for state 2, Awaiting Clear Confirmation State. * The handling of the timer(s) is in file x25_timer.c * Handling of state 0 and connection release is in af_x25.c. */ static int x25_state2_machine(struct sock *sk, struct sk_buff *skb, int frametype) { switch (frametype) { case X25_CLEAR_REQUEST: x25_write_internal(sk, X25_CLEAR_CONFIRMATION); x25_disconnect(sk, 0, skb->data[3], skb->data[4]); break; case X25_CLEAR_CONFIRMATION: x25_disconnect(sk, 0, 0, 0); break; default: break; } return 0; }
/* * State machine for state 1, Awaiting Call Accepted State. * The handling of the timer(s) is in file x25_timer.c. * Handling of state 0 and connection release is in af_x25.c. */ static int x25_state1_machine(struct sock *sk, struct sk_buff *skb, int frametype) { struct x25_address source_addr, dest_addr; switch (frametype) { case X25_CALL_ACCEPTED: { struct x25_sock *x25 = x25_sk(sk); x25_stop_timer(sk); x25->condition = 0x00; x25->vs = 0; x25->va = 0; x25->vr = 0; x25->vl = 0; x25->state = X25_STATE_3; sk->sk_state = TCP_ESTABLISHED; /* * Parse the data in the frame. */ skb_pull(skb, X25_STD_MIN_LEN); skb_pull(skb, x25_addr_ntoa(skb->data, &source_addr, &dest_addr)); skb_pull(skb, x25_parse_facilities(skb, &x25->facilities, &x25->dte_facilities, &x25->vc_facil_mask)); /* * Copy any Call User Data. */ if (skb->len >= 0) { memcpy(x25->calluserdata.cuddata, skb->data, skb->len); x25->calluserdata.cudlength = skb->len; } if (!sock_flag(sk, SOCK_DEAD)) sk->sk_state_change(sk); break; } case X25_CLEAR_REQUEST: x25_write_internal(sk, X25_CLEAR_CONFIRMATION); x25_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]); break; default: break; } return 0; }
/* * State machine for state 3, Connected State. * The handling of the timer(s) is in file x25_timer.c * Handling of state 0 and connection release is in af_x25.c. */ static int x25_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype, int ns, int nr, int q, int d, int m) { int queued = 0; int modulus; struct x25_sock *x25 = x25_sk(sk); modulus = (x25->neighbour->extended) ? X25_EMODULUS : X25_SMODULUS; switch (frametype) { case X25_RESET_REQUEST: x25_write_internal(sk, X25_RESET_CONFIRMATION); x25_stop_timer(sk); x25->condition = 0x00; x25->vs = 0; x25->vr = 0; x25->va = 0; x25->vl = 0; x25_requeue_frames(sk); break; case X25_CLEAR_REQUEST: x25_write_internal(sk, X25_CLEAR_CONFIRMATION); x25_disconnect(sk, 0, skb->data[3], skb->data[4]); break; case X25_RR: case X25_RNR: if (!x25_validate_nr(sk, nr)) { x25_clear_queues(sk); x25_write_internal(sk, X25_RESET_REQUEST); x25_start_t22timer(sk); x25->condition = 0x00; x25->vs = 0; x25->vr = 0; x25->va = 0; x25->vl = 0; x25->state = X25_STATE_4; } else { x25_frames_acked(sk, nr); if (frametype == X25_RNR) { x25->condition |= X25_COND_PEER_RX_BUSY; } else { x25->condition &= ~X25_COND_PEER_RX_BUSY; } } break; case X25_DATA: /* XXX */ x25->condition &= ~X25_COND_PEER_RX_BUSY; if ((ns != x25->vr) || !x25_validate_nr(sk, nr)) { x25_clear_queues(sk); x25_write_internal(sk, X25_RESET_REQUEST); x25_start_t22timer(sk); x25->condition = 0x00; x25->vs = 0; x25->vr = 0; x25->va = 0; x25->vl = 0; x25->state = X25_STATE_4; break; } x25_frames_acked(sk, nr); if (ns == x25->vr) { if (x25_queue_rx_frame(sk, skb, m) == 0) { x25->vr = (x25->vr + 1) % modulus; queued = 1; } else { /* Should never happen */ x25_clear_queues(sk); x25_write_internal(sk, X25_RESET_REQUEST); x25_start_t22timer(sk); x25->condition = 0x00; x25->vs = 0; x25->vr = 0; x25->va = 0; x25->vl = 0; x25->state = X25_STATE_4; break; } if (atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf / 2)) x25->condition |= X25_COND_OWN_RX_BUSY; } /* * If the window is full Ack it immediately, else * start the holdback timer. */ if (((x25->vl + x25->facilities.winsize_in) % modulus) == x25->vr) { x25->condition &= ~X25_COND_ACK_PENDING; x25_stop_timer(sk); x25_enquiry_response(sk); } else { x25->condition |= X25_COND_ACK_PENDING; x25_start_t2timer(sk); } break; case X25_INTERRUPT_CONFIRMATION: x25->intflag = 0; break; case X25_INTERRUPT: if (sock_flag(sk, SOCK_URGINLINE)) queued = !sock_queue_rcv_skb(sk, skb); else { skb_set_owner_r(skb, sk); skb_queue_tail(&x25->interrupt_in_queue, skb); queued = 1; } sk_send_sigurg(sk); x25_write_internal(sk, X25_INTERRUPT_CONFIRMATION); break; default: printk(KERN_WARNING "x25: unknown %02X in state 3\n", frametype); break; } return queued; }