Orange Pi5 kernel

// 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;
<------>bool up;
<------>spinlock_t up_lock; /* Protects "up" */
};
 
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;
 
<------>if (skb_cow(skb, 1)) {
<------><------>kfree_skb(skb);
<------><------>return NET_RX_DROP;
<------>}
 
<------>skb_push(skb, 1);
<------>skb_reset_network_header(skb);
 
<------>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);
 
<------>skb_reset_network_header(skb);
<------>skb->protocol = hdlc_type_trans(skb, dev);
 
<------>if (dev_nit_active(dev))
<------><------>dev_queue_xmit_nit(skb, dev);
 
<------>hdlc->xmit(skb, dev); /* Ignore return value :-( */
}
 
 
 
static netdev_tx_t x25_xmit(struct sk_buff *skb, struct net_device *dev)
{
<------>hdlc_device *hdlc = dev_to_hdlc(dev);
<------>struct x25_state *x25st = state(hdlc);
<------>int result;
 
<------>/* There should be a pseudo header of 1 byte added by upper layers.
<------> * Check to make sure it is there before reading it.
<------> */
<------>if (skb->len < 1) {
<------><------>kfree_skb(skb);
<------><------>return NETDEV_TX_OK;
<------>}
 
<------>spin_lock_bh(&x25st->up_lock);
<------>if (!x25st->up) {
<------><------>spin_unlock_bh(&x25st->up_lock);
<------><------>kfree_skb(skb);
<------><------>return NETDEV_TX_OK;
<------>}
 
<------>switch (skb->data[0]) {
<------>case X25_IFACE_DATA:	/* Data to be transmitted */
<------><------>skb_pull(skb, 1);
<------><------>skb_reset_network_header(skb);
<------><------>if ((result = lapb_data_request(dev, skb)) != LAPB_OK)
<------><------><------>dev_kfree_skb(skb);
<------><------>spin_unlock_bh(&x25st->up_lock);
<------><------>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;
<------>}
 
<------>spin_unlock_bh(&x25st->up_lock);
<------>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 x25_state *x25st = state(hdlc);
<------>struct lapb_parms_struct params;
<------>int result;
 
<------>result = lapb_register(dev, &cb);
<------>if (result != LAPB_OK)
<------><------>return -ENOMEM;
 
<------>result = lapb_getparms(dev, &params);
<------>if (result != LAPB_OK)
<------><------>return -EINVAL;
 
<------>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 -EINVAL;
 
<------>spin_lock_bh(&x25st->up_lock);
<------>x25st->up = true;
<------>spin_unlock_bh(&x25st->up_lock);
 
<------>return 0;
}
 
 
 
static void x25_close(struct net_device *dev)
{
<------>hdlc_device *hdlc = dev_to_hdlc(dev);
<------>struct x25_state *x25st = state(hdlc);
 
<------>spin_lock_bh(&x25st->up_lock);
<------>x25st->up = false;
<------>spin_unlock_bh(&x25st->up_lock);
 
<------>lapb_unregister(dev);
}
 
 
 
static int x25_rx(struct sk_buff *skb)
{
<------>struct net_device *dev = skb->dev;
<------>hdlc_device *hdlc = dev_to_hdlc(dev);
<------>struct x25_state *x25st = state(hdlc);
 
<------>if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
<------><------>dev->stats.rx_dropped++;
<------><------>return NET_RX_DROP;
<------>}
 
<------>spin_lock_bh(&x25st->up_lock);
<------>if (!x25st->up) {
<------><------>spin_unlock_bh(&x25st->up_lock);
<------><------>kfree_skb(skb);
<------><------>dev->stats.rx_dropped++;
<------><------>return NET_RX_DROP;
<------>}
 
<------>if (lapb_data_received(dev, skb) == LAPB_OK) {
<------><------>spin_unlock_bh(&x25st->up_lock);
<------><------>return NET_RX_SUCCESS;
<------>}
 
<------>spin_unlock_bh(&x25st->up_lock);
<------>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);
<------><------>state(hdlc)->up = false;
<------><------>spin_lock_init(&state(hdlc)->up_lock);
 
<------><------>/* There's no header_ops so hard_header_len should be 0. */
<------><------>dev->hard_header_len = 0;
<------><------>/* When transmitting data:
<------><------> * first we'll remove a pseudo header of 1 byte,
<------><------> * then we'll prepend an LAPB header of at most 3 bytes.
<------><------> */
<------><------>dev->needed_headroom = 3 - 1;
 
<------><------>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");