--- /dev/null
+/*
+ * Generic HDLC support routines for Linux
+ * Cisco HDLC support
+ *
+ * Copyright (C) 2000 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License
+ * as published by the Free Software Foundation.
+ */
+
+#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;
+ 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
+ printk(KERN_DEBUG "%s: cisco_hard_header called\n", dev->name);
+#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 cisco_keepalive_send()\n");
+ 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_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) {
+ struct in_ifaddr **ifap = &in_dev->ifa_list;
+
+ while (*ifap != NULL) {
+ if (strcmp(dev->name,
+ (*ifap)->ifa_label) == 0) {
+ addr = (*ifap)->ifa_local;
+ mask = (*ifap)->ifa_mask;
+ break;
+ }
+ ifap = &(*ifap)->ifa_next;
+ }
+
+ 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(unsigned long arg)
+{
+ struct net_device *dev = (struct net_device *)arg;
+ hdlc_device *hdlc = dev_to_hdlc(dev);
+ struct cisco_state *st = state(hdlc);
+
+ 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;
+ st->timer.function = cisco_timer;
+ st->timer.data = arg;
+ 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);
+
+ init_timer(&st->timer);
+ st->timer.expires = jiffies + HZ; /* First poll after 1 s */
+ st->timer.function = cisco_timer;
+ st->timer.data = (unsigned long)dev;
+ 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->type = ARPHRD_CISCO;
+ 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");
Code Review / kvmfornfv.git / blobdiff