1 files changed, 404 insertions, 0 deletions

diff --git a/drivers/net/wan/hdlc_cisco.c b/drivers/net/wan/hdlc_cisco.c
new file mode 100644
index 000000000..cb5898f7d
--- /dev/null
+++ b/drivers/net/wan/hdlc_cisco.c
@@ -0,0 +1,404 @@
+// 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");