Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Generic HDLC support routines for Linux
 * Cisco HDLC support
 *
 * Copyright (C) 2000 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
 */
 
#include <linux/errno.h>
#include <linux/hdlc.h>
#include <linux/if_arp.h>
#include <linux/inetdevice.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pkt_sched.h>
#include <linux/poll.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
 
#undef DEBUG_HARD_HEADER
 
#define CISCO_MULTICAST		0x8F	/* Cisco multicast address */
#define CISCO_UNICAST		0x0F	/* Cisco unicast address */
#define CISCO_KEEPALIVE		0x8035	/* Cisco keepalive protocol */
#define CISCO_SYS_INFO		0x2000	/* Cisco interface/system info */
#define CISCO_ADDR_REQ		0	/* Cisco address request */
#define CISCO_ADDR_REPLY	1	/* Cisco address reply */
#define CISCO_KEEPALIVE_REQ	2	/* Cisco keepalive request */
 
 
struct hdlc_header {
<------>u8 address;
<------>u8 control;
<------>__be16 protocol;
}__packed;
 
 
struct cisco_packet {
<------>__be32 type;		/* code */
<------>__be32 par1;
<------>__be32 par2;
<------>__be16 rel;		/* reliability */
<------>__be32 time;
}__packed;
#define	CISCO_PACKET_LEN	18
#define	CISCO_BIG_PACKET_LEN	20
 
 
struct cisco_state {
<------>cisco_proto settings;
 
<------>struct timer_list timer;
<------>struct net_device *dev;
<------>spinlock_t lock;
<------>unsigned long last_poll;
<------>int up;
<------>u32 txseq; /* TX sequence number, 0 = none */
<------>u32 rxseq; /* RX sequence number */
};
 
 
static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr);
 
 
static inline struct cisco_state* state(hdlc_device *hdlc)
{
<------>return (struct cisco_state *)hdlc->state;
}
 
 
static int cisco_hard_header(struct sk_buff *skb, struct net_device *dev,
<------><------><------>     u16 type, const void *daddr, const void *saddr,
<------><------><------>     unsigned int len)
{
<------>struct hdlc_header *data;
#ifdef DEBUG_HARD_HEADER
<------>netdev_dbg(dev, "%s called\n", __func__);
#endif
 
<------>skb_push(skb, sizeof(struct hdlc_header));
<------>data = (struct hdlc_header*)skb->data;
<------>if (type == CISCO_KEEPALIVE)
<------><------>data->address = CISCO_MULTICAST;
<------>else
<------><------>data->address = CISCO_UNICAST;
<------>data->control = 0;
<------>data->protocol = htons(type);
 
<------>return sizeof(struct hdlc_header);
}
 
 
 
static void cisco_keepalive_send(struct net_device *dev, u32 type,
<------><------><------><------> __be32 par1, __be32 par2)
{
<------>struct sk_buff *skb;
<------>struct cisco_packet *data;
 
<------>skb = dev_alloc_skb(sizeof(struct hdlc_header) +
<------><------><------>    sizeof(struct cisco_packet));
<------>if (!skb) {
<------><------>netdev_warn(dev, "Memory squeeze on %s()\n", __func__);
<------><------>return;
<------>}
<------>skb_reserve(skb, 4);
<------>cisco_hard_header(skb, dev, CISCO_KEEPALIVE, NULL, NULL, 0);
<------>data = (struct cisco_packet*)(skb->data + 4);
 
<------>data->type = htonl(type);
<------>data->par1 = par1;
<------>data->par2 = par2;
<------>data->rel = cpu_to_be16(0xFFFF);
<------>/* we will need do_div here if 1000 % HZ != 0 */
<------>data->time = htonl((jiffies - INITIAL_JIFFIES) * (1000 / HZ));
 
<------>skb_put(skb, sizeof(struct cisco_packet));
<------>skb->priority = TC_PRIO_CONTROL;
<------>skb->dev = dev;
<------>skb->protocol = htons(ETH_P_HDLC);
<------>skb_reset_network_header(skb);
 
<------>dev_queue_xmit(skb);
}
 
 
 
static __be16 cisco_type_trans(struct sk_buff *skb, struct net_device *dev)
{
<------>struct hdlc_header *data = (struct hdlc_header*)skb->data;
 
<------>if (skb->len < sizeof(struct hdlc_header))
<------><------>return cpu_to_be16(ETH_P_HDLC);
 
<------>if (data->address != CISCO_MULTICAST &&
<------>    data->address != CISCO_UNICAST)
<------><------>return cpu_to_be16(ETH_P_HDLC);
 
<------>switch (data->protocol) {
<------>case cpu_to_be16(ETH_P_IP):
<------>case cpu_to_be16(ETH_P_IPX):
<------>case cpu_to_be16(ETH_P_IPV6):
<------><------>skb_pull(skb, sizeof(struct hdlc_header));
<------><------>return data->protocol;
<------>default:
<------><------>return cpu_to_be16(ETH_P_HDLC);
<------>}
}
 
 
static int cisco_rx(struct sk_buff *skb)
{
<------>struct net_device *dev = skb->dev;
<------>hdlc_device *hdlc = dev_to_hdlc(dev);
<------>struct cisco_state *st = state(hdlc);
<------>struct hdlc_header *data = (struct hdlc_header*)skb->data;
<------>struct cisco_packet *cisco_data;
<------>struct in_device *in_dev;
<------>__be32 addr, mask;
<------>u32 ack;
 
<------>if (skb->len < sizeof(struct hdlc_header))
<------><------>goto rx_error;
 
<------>if (data->address != CISCO_MULTICAST &&
<------>    data->address != CISCO_UNICAST)
<------><------>goto rx_error;
 
<------>switch (ntohs(data->protocol)) {
<------>case CISCO_SYS_INFO:
<------><------>/* Packet is not needed, drop it. */
<------><------>dev_kfree_skb_any(skb);
<------><------>return NET_RX_SUCCESS;
 
<------>case CISCO_KEEPALIVE:
<------><------>if ((skb->len != sizeof(struct hdlc_header) +
<------><------>     CISCO_PACKET_LEN) &&
<------><------>    (skb->len != sizeof(struct hdlc_header) +
<------><------>     CISCO_BIG_PACKET_LEN)) {
<------><------><------>netdev_info(dev, "Invalid length of Cisco control packet (%d bytes)\n",
<------><------><------><------>    skb->len);
<------><------><------>goto rx_error;
<------><------>}
 
<------><------>cisco_data = (struct cisco_packet*)(skb->data + sizeof
<------><------><------><------><------><------>    (struct hdlc_header));
 
<------><------>switch (ntohl (cisco_data->type)) {
<------><------>case CISCO_ADDR_REQ: /* Stolen from syncppp.c :-) */
<------><------><------>rcu_read_lock();
<------><------><------>in_dev = __in_dev_get_rcu(dev);
<------><------><------>addr = 0;
<------><------><------>mask = ~cpu_to_be32(0); /* is the mask correct? */
 
<------><------><------>if (in_dev != NULL) {
<------><------><------><------>const struct in_ifaddr *ifa;
 
<------><------><------><------>in_dev_for_each_ifa_rcu(ifa, in_dev) {
<------><------><------><------><------>if (strcmp(dev->name,
<------><------><------><------><------><------>   ifa->ifa_label) == 0) {
<------><------><------><------><------><------>addr = ifa->ifa_local;
<------><------><------><------><------><------>mask = ifa->ifa_mask;
<------><------><------><------><------><------>break;
<------><------><------><------><------>}
<------><------><------><------>}
 
<------><------><------><------>cisco_keepalive_send(dev, CISCO_ADDR_REPLY,
<------><------><------><------><------><------>     addr, mask);
<------><------><------>}
<------><------><------>rcu_read_unlock();
<------><------><------>dev_kfree_skb_any(skb);
<------><------><------>return NET_RX_SUCCESS;
 
<------><------>case CISCO_ADDR_REPLY:
<------><------><------>netdev_info(dev, "Unexpected Cisco IP address reply\n");
<------><------><------>goto rx_error;
 
<------><------>case CISCO_KEEPALIVE_REQ:
<------><------><------>spin_lock(&st->lock);
<------><------><------>st->rxseq = ntohl(cisco_data->par1);
<------><------><------>ack = ntohl(cisco_data->par2);
<------><------><------>if (ack && (ack == st->txseq ||
<------><------><------><------>    /* our current REQ may be in transit */
<------><------><------><------>    ack == st->txseq - 1)) {
<------><------><------><------>st->last_poll = jiffies;
<------><------><------><------>if (!st->up) {
<------><------><------><------><------>u32 sec, min, hrs, days;
<------><------><------><------><------>sec = ntohl(cisco_data->time) / 1000;
<------><------><------><------><------>min = sec / 60; sec -= min * 60;
<------><------><------><------><------>hrs = min / 60; min -= hrs * 60;
<------><------><------><------><------>days = hrs / 24; hrs -= days * 24;
<------><------><------><------><------>netdev_info(dev, "Link up (peer uptime %ud%uh%um%us)\n",
<------><------><------><------><------><------>    days, hrs, min, sec);
<------><------><------><------><------>netif_dormant_off(dev);
<------><------><------><------><------>st->up = 1;
<------><------><------><------>}
<------><------><------>}
<------><------><------>spin_unlock(&st->lock);
 
<------><------><------>dev_kfree_skb_any(skb);
<------><------><------>return NET_RX_SUCCESS;
<------><------>} /* switch (keepalive type) */
<------>} /* switch (protocol) */
 
<------>netdev_info(dev, "Unsupported protocol %x\n", ntohs(data->protocol));
<------>dev_kfree_skb_any(skb);
<------>return NET_RX_DROP;
 
rx_error:
<------>dev->stats.rx_errors++; /* Mark error */
<------>dev_kfree_skb_any(skb);
<------>return NET_RX_DROP;
}
 
 
 
static void cisco_timer(struct timer_list *t)
{
<------>struct cisco_state *st = from_timer(st, t, timer);
<------>struct net_device *dev = st->dev;
 
<------>spin_lock(&st->lock);
<------>if (st->up &&
<------>    time_after(jiffies, st->last_poll + st->settings.timeout * HZ)) {
<------><------>st->up = 0;
<------><------>netdev_info(dev, "Link down\n");
<------><------>netif_dormant_on(dev);
<------>}
 
<------>cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ, htonl(++st->txseq),
<------><------><------>     htonl(st->rxseq));
<------>spin_unlock(&st->lock);
 
<------>st->timer.expires = jiffies + st->settings.interval * HZ;
<------>add_timer(&st->timer);
}
 
 
 
static void cisco_start(struct net_device *dev)
{
<------>hdlc_device *hdlc = dev_to_hdlc(dev);
<------>struct cisco_state *st = state(hdlc);
<------>unsigned long flags;
 
<------>spin_lock_irqsave(&st->lock, flags);
<------>st->up = st->txseq = st->rxseq = 0;
<------>spin_unlock_irqrestore(&st->lock, flags);
 
<------>st->dev = dev;
<------>timer_setup(&st->timer, cisco_timer, 0);
<------>st->timer.expires = jiffies + HZ; /* First poll after 1 s */
<------>add_timer(&st->timer);
}
 
 
 
static void cisco_stop(struct net_device *dev)
{
<------>hdlc_device *hdlc = dev_to_hdlc(dev);
<------>struct cisco_state *st = state(hdlc);
<------>unsigned long flags;
 
<------>del_timer_sync(&st->timer);
 
<------>spin_lock_irqsave(&st->lock, flags);
<------>netif_dormant_on(dev);
<------>st->up = st->txseq = 0;
<------>spin_unlock_irqrestore(&st->lock, flags);
}
 
 
static struct hdlc_proto proto = {
<------>.start		= cisco_start,
<------>.stop		= cisco_stop,
<------>.type_trans	= cisco_type_trans,
<------>.ioctl		= cisco_ioctl,
<------>.netif_rx	= cisco_rx,
<------>.module		= THIS_MODULE,
};
 
static const struct header_ops cisco_header_ops = {
<------>.create = cisco_hard_header,
};
 
static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr)
{
<------>cisco_proto __user *cisco_s = ifr->ifr_settings.ifs_ifsu.cisco;
<------>const size_t size = sizeof(cisco_proto);
<------>cisco_proto new_settings;
<------>hdlc_device *hdlc = dev_to_hdlc(dev);
<------>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_CISCO;
<------><------>if (ifr->ifr_settings.size < size) {
<------><------><------>ifr->ifr_settings.size = size; /* data size wanted */
<------><------><------>return -ENOBUFS;
<------><------>}
<------><------>if (copy_to_user(cisco_s, &state(hdlc)->settings, size))
<------><------><------>return -EFAULT;
<------><------>return 0;
 
<------>case IF_PROTO_CISCO:
<------><------>if (!capable(CAP_NET_ADMIN))
<------><------><------>return -EPERM;
 
<------><------>if (dev->flags & IFF_UP)
<------><------><------>return -EBUSY;
 
<------><------>if (copy_from_user(&new_settings, cisco_s, size))
<------><------><------>return -EFAULT;
 
<------><------>if (new_settings.interval < 1 ||
<------><------>    new_settings.timeout < 2)
<------><------><------>return -EINVAL;
 
<------><------>result = hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
<------><------>if (result)
<------><------><------>return result;
 
<------><------>result = attach_hdlc_protocol(dev, &proto,
<------><------><------><------><------>      sizeof(struct cisco_state));
<------><------>if (result)
<------><------><------>return result;
 
<------><------>memcpy(&state(hdlc)->settings, &new_settings, size);
<------><------>spin_lock_init(&state(hdlc)->lock);
<------><------>dev->header_ops = &cisco_header_ops;
<------><------>dev->hard_header_len = sizeof(struct hdlc_header);
<------><------>dev->type = ARPHRD_CISCO;
<------><------>call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
<------><------>netif_dormant_on(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("Cisco HDLC protocol support for generic HDLC");
MODULE_LICENSE("GPL v2");