Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <linux/socket.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <linux/in.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/timer.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/sockios.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/spinlock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/net.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <linux/gfp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <net/ax25.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include <linux/inet.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #include <linux/netdevice.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #include <linux/skbuff.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) #include <net/sock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) #include <linux/fcntl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) #include <linux/interrupt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) void ax25_ds_nr_error_recovery(ax25_cb *ax25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	ax25_ds_establish_data_link(ax25);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34)  *	dl1bke 960114: transmit I frames on DAMA poll
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) void ax25_ds_enquiry_response(ax25_cb *ax25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	ax25_cb *ax25o;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	/* Please note that neither DK4EG's nor DG2FEF's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	 * DAMA spec mention the following behaviour as seen
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	 * with TheFirmware:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	 * 	DB0ACH->DL1BKE <RR C P R0> [DAMA]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	 *	DL1BKE->DB0ACH <I NR=0 NS=0>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 	 *	DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 	 *	DL1BKE->DB0ACH <RR R F R0>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	 * The Flexnet DAMA Master implementation apparently
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 	 * insists on the "proper" AX.25 behaviour:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	 * 	DB0ACH->DL1BKE <RR C P R0> [DAMA]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	 *	DL1BKE->DB0ACH <RR R F R0>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	 *	DL1BKE->DB0ACH <I NR=0 NS=0>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	 *	DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	 * Flexnet refuses to send us *any* I frame if we send
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	 * a REJ in case AX25_COND_REJECT is set. It is superfluous in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	 * this mode anyway (a RR or RNR invokes the retransmission).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	 * Is this a Flexnet bug?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	ax25_std_enquiry_response(ax25);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	if (!(ax25->condition & AX25_COND_PEER_RX_BUSY)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 		ax25_requeue_frames(ax25);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 		ax25_kick(ax25);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	if (ax25->state == AX25_STATE_1 || ax25->state == AX25_STATE_2 || skb_peek(&ax25->ack_queue) != NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 		ax25_ds_t1_timeout(ax25);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 		ax25->n2count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	ax25_start_t3timer(ax25);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	ax25_ds_set_timer(ax25->ax25_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	spin_lock(&ax25_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	ax25_for_each(ax25o, &ax25_list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 		if (ax25o == ax25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 		if (ax25o->ax25_dev != ax25->ax25_dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 		if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 			ax25_ds_t1_timeout(ax25o);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 		if (!(ax25o->condition & AX25_COND_PEER_RX_BUSY) && ax25o->state == AX25_STATE_3) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 			ax25_requeue_frames(ax25o);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 			ax25_kick(ax25o);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 		if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2 || skb_peek(&ax25o->ack_queue) != NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 			ax25_ds_t1_timeout(ax25o);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 		/* do not start T3 for listening sockets (tnx DD8NE) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 		if (ax25o->state != AX25_STATE_0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 			ax25_start_t3timer(ax25o);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	spin_unlock(&ax25_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) void ax25_ds_establish_data_link(ax25_cb *ax25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	ax25->condition &= AX25_COND_DAMA_MODE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	ax25->n2count    = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	ax25_calculate_t1(ax25);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	ax25_start_t1timer(ax25);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	ax25_stop_t2timer(ax25);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	ax25_start_t3timer(ax25);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)  *	:::FIXME:::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)  *	This is a kludge. Not all drivers recognize kiss commands.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)  *	We need a driver level  request to switch duplex mode, that does
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121)  *	either SCC changing, PI config or KISS as required. Currently
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)  *	this request isn't reliable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) static void ax25_kiss_cmd(ax25_dev *ax25_dev, unsigned char cmd, unsigned char param)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	struct sk_buff *skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 	unsigned char *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 	if (ax25_dev->dev == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	if ((skb = alloc_skb(2, GFP_ATOMIC)) == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	skb_reset_network_header(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	p = skb_put(skb, 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	*p++ = cmd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	*p++ = param;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	skb->protocol = ax25_type_trans(skb, ax25_dev->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	dev_queue_xmit(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147)  *	A nasty problem arises if we count the number of DAMA connections
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)  *	wrong, especially when connections on the device already existed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)  *	and our network node (or the sysop) decides to turn on DAMA Master
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)  *	mode. We thus flag the 'real' slave connections with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)  *	ax25->dama_slave=1 and look on every disconnect if still slave
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)  *	connections exist.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) static int ax25_check_dama_slave(ax25_dev *ax25_dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	ax25_cb *ax25;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	int res = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	spin_lock(&ax25_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	ax25_for_each(ax25, &ax25_list)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 		if (ax25->ax25_dev == ax25_dev && (ax25->condition & AX25_COND_DAMA_MODE) && ax25->state > AX25_STATE_1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 			res = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	spin_unlock(&ax25_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	return res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) static void ax25_dev_dama_on(ax25_dev *ax25_dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	if (ax25_dev == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	if (ax25_dev->dama.slave == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 		ax25_kiss_cmd(ax25_dev, 5, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	ax25_dev->dama.slave = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 	ax25_ds_set_timer(ax25_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) void ax25_dev_dama_off(ax25_dev *ax25_dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	if (ax25_dev == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 	if (ax25_dev->dama.slave && !ax25_check_dama_slave(ax25_dev)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 		ax25_kiss_cmd(ax25_dev, 5, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 		ax25_dev->dama.slave = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 		ax25_ds_del_timer(ax25_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) void ax25_dama_on(ax25_cb *ax25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	ax25_dev_dama_on(ax25->ax25_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	ax25->condition |= AX25_COND_DAMA_MODE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) void ax25_dama_off(ax25_cb *ax25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	ax25->condition &= ~AX25_COND_DAMA_MODE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	ax25_dev_dama_off(ax25->ax25_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) }