1 /* 2 * This program is free software; you can redistribute it and/or modify 3 * it under the terms of the GNU General Public License as published by 4 * the Free Software Foundation; either version 2 of the License, or 5 * (at your option) any later version. 6 * 7 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) 8 */ 9 #include <linux/errno.h> 10 #include <linux/types.h> 11 #include <linux/socket.h> 12 #include <linux/in.h> 13 #include <linux/kernel.h> 14 #include <linux/timer.h> 15 #include <linux/string.h> 16 #include <linux/sockios.h> 17 #include <linux/net.h> 18 #include <net/ax25.h> 19 #include <linux/inet.h> 20 #include <linux/netdevice.h> 21 #include <linux/skbuff.h> 22 #include <net/sock.h> 23 #include <asm/uaccess.h> 24 #include <asm/system.h> 25 #include <linux/fcntl.h> 26 #include <linux/mm.h> 27 #include <linux/interrupt.h> 28 29 /* 30 * The following routines are taken from page 170 of the 7th ARRL Computer 31 * Networking Conference paper, as is the whole state machine. 32 */ 33 34 void ax25_std_nr_error_recovery(ax25_cb *ax25) 35 { 36 ax25_std_establish_data_link(ax25); 37 } 38 39 void ax25_std_establish_data_link(ax25_cb *ax25) 40 { 41 ax25->condition = 0x00; 42 ax25->n2count = 0; 43 44 if (ax25->modulus == AX25_MODULUS) 45 ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND); 46 else 47 ax25_send_control(ax25, AX25_SABME, AX25_POLLON, AX25_COMMAND); 48 49 ax25_calculate_t1(ax25); 50 ax25_stop_idletimer(ax25); 51 ax25_stop_t3timer(ax25); 52 ax25_stop_t2timer(ax25); 53 ax25_start_t1timer(ax25); 54 } 55 56 void ax25_std_transmit_enquiry(ax25_cb *ax25) 57 { 58 if (ax25->condition & AX25_COND_OWN_RX_BUSY) 59 ax25_send_control(ax25, AX25_RNR, AX25_POLLON, AX25_COMMAND); 60 else 61 ax25_send_control(ax25, AX25_RR, AX25_POLLON, AX25_COMMAND); 62 63 ax25->condition &= ~AX25_COND_ACK_PENDING; 64 65 ax25_calculate_t1(ax25); 66 ax25_start_t1timer(ax25); 67 } 68 69 void ax25_std_enquiry_response(ax25_cb *ax25) 70 { 71 if (ax25->condition & AX25_COND_OWN_RX_BUSY) 72 ax25_send_control(ax25, AX25_RNR, AX25_POLLON, AX25_RESPONSE); 73 else 74 ax25_send_control(ax25, AX25_RR, AX25_POLLON, AX25_RESPONSE); 75 76 ax25->condition &= ~AX25_COND_ACK_PENDING; 77 } 78 79 void ax25_std_timeout_response(ax25_cb *ax25) 80 { 81 if (ax25->condition & AX25_COND_OWN_RX_BUSY) 82 ax25_send_control(ax25, AX25_RNR, AX25_POLLOFF, AX25_RESPONSE); 83 else 84 ax25_send_control(ax25, AX25_RR, AX25_POLLOFF, AX25_RESPONSE); 85 86 ax25->condition &= ~AX25_COND_ACK_PENDING; 87 } 88