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 <linux/fcntl.h> 25 #include <linux/mm.h> 26 #include <linux/interrupt.h> 27 28 /* 29 * The following routines are taken from page 170 of the 7th ARRL Computer 30 * Networking Conference paper, as is the whole state machine. 31 */ 32 33 void ax25_std_nr_error_recovery(ax25_cb *ax25) 34 { 35 ax25_std_establish_data_link(ax25); 36 } 37 38 void ax25_std_establish_data_link(ax25_cb *ax25) 39 { 40 ax25->condition = 0x00; 41 ax25->n2count = 0; 42 43 if (ax25->modulus == AX25_MODULUS) 44 ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND); 45 else 46 ax25_send_control(ax25, AX25_SABME, AX25_POLLON, AX25_COMMAND); 47 48 ax25_calculate_t1(ax25); 49 ax25_stop_idletimer(ax25); 50 ax25_stop_t3timer(ax25); 51 ax25_stop_t2timer(ax25); 52 ax25_start_t1timer(ax25); 53 } 54 55 void ax25_std_transmit_enquiry(ax25_cb *ax25) 56 { 57 if (ax25->condition & AX25_COND_OWN_RX_BUSY) 58 ax25_send_control(ax25, AX25_RNR, AX25_POLLON, AX25_COMMAND); 59 else 60 ax25_send_control(ax25, AX25_RR, AX25_POLLON, AX25_COMMAND); 61 62 ax25->condition &= ~AX25_COND_ACK_PENDING; 63 64 ax25_calculate_t1(ax25); 65 ax25_start_t1timer(ax25); 66 } 67 68 void ax25_std_enquiry_response(ax25_cb *ax25) 69 { 70 if (ax25->condition & AX25_COND_OWN_RX_BUSY) 71 ax25_send_control(ax25, AX25_RNR, AX25_POLLON, AX25_RESPONSE); 72 else 73 ax25_send_control(ax25, AX25_RR, AX25_POLLON, AX25_RESPONSE); 74 75 ax25->condition &= ~AX25_COND_ACK_PENDING; 76 } 77 78 void ax25_std_timeout_response(ax25_cb *ax25) 79 { 80 if (ax25->condition & AX25_COND_OWN_RX_BUSY) 81 ax25_send_control(ax25, AX25_RNR, AX25_POLLOFF, AX25_RESPONSE); 82 else 83 ax25_send_control(ax25, AX25_RR, AX25_POLLOFF, AX25_RESPONSE); 84 85 ax25->condition &= ~AX25_COND_ACK_PENDING; 86 } 87