/* * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de) */ #include <linux/errno.h> #include <linux/types.h> #include <linux/socket.h> #include <linux/in.h> #include <linux/kernel.h> #include <linux/timer.h> #include <linux/string.h> #include <linux/sockios.h> #include <linux/spinlock.h> #include <linux/net.h> #include <linux/gfp.h> #include <net/ax25.h> #include <linux/inet.h> #include <linux/netdevice.h> #include <linux/skbuff.h> #include <net/sock.h> #include <linux/uaccess.h> #include <linux/fcntl.h> #include <linux/mm.h> #include <linux/interrupt.h> void ax25_ds_nr_error_recovery(ax25_cb *ax25) { ax25_ds_establish_data_link(ax25); } /* * dl1bke 960114: transmit I frames on DAMA poll */ void ax25_ds_enquiry_response(ax25_cb *ax25) { ax25_cb *ax25o; /* Please note that neither DK4EG's nor DG2FEF's * DAMA spec mention the following behaviour as seen * with TheFirmware: * * DB0ACH->DL1BKE <RR C P R0> [DAMA] * DL1BKE->DB0ACH <I NR=0 NS=0> * DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5> * DL1BKE->DB0ACH <RR R F R0> * * The Flexnet DAMA Master implementation apparently * insists on the "proper" AX.25 behaviour: * * DB0ACH->DL1BKE <RR C P R0> [DAMA] * DL1BKE->DB0ACH <RR R F R0> * DL1BKE->DB0ACH <I NR=0 NS=0> * DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5> * * Flexnet refuses to send us *any* I frame if we send * a REJ in case AX25_COND_REJECT is set. It is superfluous in * this mode anyway (a RR or RNR invokes the retransmission). * Is this a Flexnet bug? */ ax25_std_enquiry_response(ax25); if (!(ax25->condition & AX25_COND_PEER_RX_BUSY)) { ax25_requeue_frames(ax25); ax25_kick(ax25); } if (ax25->state == AX25_STATE_1 || ax25->state == AX25_STATE_2 || skb_peek(&ax25->ack_queue) != NULL) ax25_ds_t1_timeout(ax25); else ax25->n2count = 0; ax25_start_t3timer(ax25); ax25_ds_set_timer(ax25->ax25_dev); spin_lock(&ax25_list_lock); ax25_for_each(ax25o, &ax25_list) { if (ax25o == ax25) continue; if (ax25o->ax25_dev != ax25->ax25_dev) continue; if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2) { ax25_ds_t1_timeout(ax25o); continue; } if (!(ax25o->condition & AX25_COND_PEER_RX_BUSY) && ax25o->state == AX25_STATE_3) { ax25_requeue_frames(ax25o); ax25_kick(ax25o); } if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2 || skb_peek(&ax25o->ack_queue) != NULL) ax25_ds_t1_timeout(ax25o); /* do not start T3 for listening sockets (tnx DD8NE) */ if (ax25o->state != AX25_STATE_0) ax25_start_t3timer(ax25o); } spin_unlock(&ax25_list_lock); } void ax25_ds_establish_data_link(ax25_cb *ax25) { ax25->condition &= AX25_COND_DAMA_MODE; ax25->n2count = 0; ax25_calculate_t1(ax25); ax25_start_t1timer(ax25); ax25_stop_t2timer(ax25); ax25_start_t3timer(ax25); } /* * :::FIXME::: * This is a kludge. Not all drivers recognize kiss commands. * We need a driver level request to switch duplex mode, that does * either SCC changing, PI config or KISS as required. Currently * this request isn't reliable. */ static void ax25_kiss_cmd(ax25_dev *ax25_dev, unsigned char cmd, unsigned char param) { struct sk_buff *skb; unsigned char *p; if (ax25_dev->dev == NULL) return; if ((skb = alloc_skb(2, GFP_ATOMIC)) == NULL) return; skb_reset_network_header(skb); p = skb_put(skb, 2); *p++ = cmd; *p++ = param; skb->protocol = ax25_type_trans(skb, ax25_dev->dev); dev_queue_xmit(skb); } /* * A nasty problem arises if we count the number of DAMA connections * wrong, especially when connections on the device already existed * and our network node (or the sysop) decides to turn on DAMA Master * mode. We thus flag the 'real' slave connections with * ax25->dama_slave=1 and look on every disconnect if still slave * connections exist. */ static int ax25_check_dama_slave(ax25_dev *ax25_dev) { ax25_cb *ax25; int res = 0; spin_lock(&ax25_list_lock); ax25_for_each(ax25, &ax25_list) if (ax25->ax25_dev == ax25_dev && (ax25->condition & AX25_COND_DAMA_MODE) && ax25->state > AX25_STATE_1) { res = 1; break; } spin_unlock(&ax25_list_lock); return res; } static void ax25_dev_dama_on(ax25_dev *ax25_dev) { if (ax25_dev == NULL) return; if (ax25_dev->dama.slave == 0) ax25_kiss_cmd(ax25_dev, 5, 1); ax25_dev->dama.slave = 1; ax25_ds_set_timer(ax25_dev); } void ax25_dev_dama_off(ax25_dev *ax25_dev) { if (ax25_dev == NULL) return; if (ax25_dev->dama.slave && !ax25_check_dama_slave(ax25_dev)) { ax25_kiss_cmd(ax25_dev, 5, 0); ax25_dev->dama.slave = 0; ax25_ds_del_timer(ax25_dev); } } void ax25_dama_on(ax25_cb *ax25) { ax25_dev_dama_on(ax25->ax25_dev); ax25->condition |= AX25_COND_DAMA_MODE; } void ax25_dama_off(ax25_cb *ax25) { ax25->condition &= ~AX25_COND_DAMA_MODE; ax25_dev_dama_off(ax25->ax25_dev); }