linux_dsm_epyc7002/drivers/net/wan/hdlc_x25.c
Martin Schiller f362e5fe0f wan/hdlc_x25: make lapb params configurable
This enables you to configure mode (DTE/DCE), Modulo, Window, T1, T2, N2 via
sethdlc (which needs to be patched as well).

Signed-off-by: Martin Schiller <ms@dev.tdt.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-21 11:41:36 +01:00

316 lines
6.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Generic HDLC support routines for Linux
* X.25 support
*
* Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
*/
#include <linux/errno.h>
#include <linux/gfp.h>
#include <linux/hdlc.h>
#include <linux/if_arp.h>
#include <linux/inetdevice.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/lapb.h>
#include <linux/module.h>
#include <linux/pkt_sched.h>
#include <linux/poll.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <net/x25device.h>
struct x25_state {
x25_hdlc_proto settings;
};
static int x25_ioctl(struct net_device *dev, struct ifreq *ifr);
static struct x25_state *state(hdlc_device *hdlc)
{
return hdlc->state;
}
/* These functions are callbacks called by LAPB layer */
static void x25_connect_disconnect(struct net_device *dev, int reason, int code)
{
struct sk_buff *skb;
unsigned char *ptr;
if ((skb = dev_alloc_skb(1)) == NULL) {
netdev_err(dev, "out of memory\n");
return;
}
ptr = skb_put(skb, 1);
*ptr = code;
skb->protocol = x25_type_trans(skb, dev);
netif_rx(skb);
}
static void x25_connected(struct net_device *dev, int reason)
{
x25_connect_disconnect(dev, reason, X25_IFACE_CONNECT);
}
static void x25_disconnected(struct net_device *dev, int reason)
{
x25_connect_disconnect(dev, reason, X25_IFACE_DISCONNECT);
}
static int x25_data_indication(struct net_device *dev, struct sk_buff *skb)
{
unsigned char *ptr;
skb_push(skb, 1);
if (skb_cow(skb, 1))
return NET_RX_DROP;
ptr = skb->data;
*ptr = X25_IFACE_DATA;
skb->protocol = x25_type_trans(skb, dev);
return netif_rx(skb);
}
static void x25_data_transmit(struct net_device *dev, struct sk_buff *skb)
{
hdlc_device *hdlc = dev_to_hdlc(dev);
hdlc->xmit(skb, dev); /* Ignore return value :-( */
}
static netdev_tx_t x25_xmit(struct sk_buff *skb, struct net_device *dev)
{
int result;
/* X.25 to LAPB */
switch (skb->data[0]) {
case X25_IFACE_DATA: /* Data to be transmitted */
skb_pull(skb, 1);
if ((result = lapb_data_request(dev, skb)) != LAPB_OK)
dev_kfree_skb(skb);
return NETDEV_TX_OK;
case X25_IFACE_CONNECT:
if ((result = lapb_connect_request(dev))!= LAPB_OK) {
if (result == LAPB_CONNECTED)
/* Send connect confirm. msg to level 3 */
x25_connected(dev, 0);
else
netdev_err(dev, "LAPB connect request failed, error code = %i\n",
result);
}
break;
case X25_IFACE_DISCONNECT:
if ((result = lapb_disconnect_request(dev)) != LAPB_OK) {
if (result == LAPB_NOTCONNECTED)
/* Send disconnect confirm. msg to level 3 */
x25_disconnected(dev, 0);
else
netdev_err(dev, "LAPB disconnect request failed, error code = %i\n",
result);
}
break;
default: /* to be defined */
break;
}
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
static int x25_open(struct net_device *dev)
{
static const struct lapb_register_struct cb = {
.connect_confirmation = x25_connected,
.connect_indication = x25_connected,
.disconnect_confirmation = x25_disconnected,
.disconnect_indication = x25_disconnected,
.data_indication = x25_data_indication,
.data_transmit = x25_data_transmit,
};
hdlc_device *hdlc = dev_to_hdlc(dev);
struct lapb_parms_struct params;
int result;
result = lapb_register(dev, &cb);
if (result != LAPB_OK)
return result;
result = lapb_getparms(dev, &params);
if (result != LAPB_OK)
return result;
if (state(hdlc)->settings.dce)
params.mode = params.mode | LAPB_DCE;
if (state(hdlc)->settings.modulo == 128)
params.mode = params.mode | LAPB_EXTENDED;
params.window = state(hdlc)->settings.window;
params.t1 = state(hdlc)->settings.t1;
params.t2 = state(hdlc)->settings.t2;
params.n2 = state(hdlc)->settings.n2;
result = lapb_setparms(dev, &params);
if (result != LAPB_OK)
return result;
return 0;
}
static void x25_close(struct net_device *dev)
{
lapb_unregister(dev);
}
static int x25_rx(struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
dev->stats.rx_dropped++;
return NET_RX_DROP;
}
if (lapb_data_received(dev, skb) == LAPB_OK)
return NET_RX_SUCCESS;
dev->stats.rx_errors++;
dev_kfree_skb_any(skb);
return NET_RX_DROP;
}
static struct hdlc_proto proto = {
.open = x25_open,
.close = x25_close,
.ioctl = x25_ioctl,
.netif_rx = x25_rx,
.xmit = x25_xmit,
.module = THIS_MODULE,
};
static int x25_ioctl(struct net_device *dev, struct ifreq *ifr)
{
x25_hdlc_proto __user *x25_s = ifr->ifr_settings.ifs_ifsu.x25;
const size_t size = sizeof(x25_hdlc_proto);
hdlc_device *hdlc = dev_to_hdlc(dev);
x25_hdlc_proto new_settings;
int result;
switch (ifr->ifr_settings.type) {
case IF_GET_PROTO:
if (dev_to_hdlc(dev)->proto != &proto)
return -EINVAL;
ifr->ifr_settings.type = IF_PROTO_X25;
if (ifr->ifr_settings.size < size) {
ifr->ifr_settings.size = size; /* data size wanted */
return -ENOBUFS;
}
if (copy_to_user(x25_s, &state(hdlc)->settings, size))
return -EFAULT;
return 0;
case IF_PROTO_X25:
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (dev->flags & IFF_UP)
return -EBUSY;
/* backward compatibility */
if (ifr->ifr_settings.size = 0) {
new_settings.dce = 0;
new_settings.modulo = 8;
new_settings.window = 7;
new_settings.t1 = 3;
new_settings.t2 = 1;
new_settings.n2 = 10;
}
else {
if (copy_from_user(&new_settings, x25_s, size))
return -EFAULT;
if ((new_settings.dce != 0 &&
new_settings.dce != 1) ||
(new_settings.modulo != 8 &&
new_settings.modulo != 128) ||
new_settings.window < 1 ||
(new_settings.modulo == 8 &&
new_settings.window > 7) ||
(new_settings.modulo == 128 &&
new_settings.window > 127) ||
new_settings.t1 < 1 ||
new_settings.t1 > 255 ||
new_settings.t2 < 1 ||
new_settings.t2 > 255 ||
new_settings.n2 < 1 ||
new_settings.n2 > 255)
return -EINVAL;
}
result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
if (result)
return result;
if ((result = attach_hdlc_protocol(dev, &proto,
sizeof(struct x25_state))))
return result;
memcpy(&state(hdlc)->settings, &new_settings, size);
dev->type = ARPHRD_X25;
call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
netif_dormant_off(dev);
return 0;
}
return -EINVAL;
}
static int __init mod_init(void)
{
register_hdlc_protocol(&proto);
return 0;
}
static void __exit mod_exit(void)
{
unregister_hdlc_protocol(&proto);
}
module_init(mod_init);
module_exit(mod_exit);
MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
MODULE_DESCRIPTION("X.25 protocol support for generic HDLC");
MODULE_LICENSE("GPL v2");