linux/drivers/net/wan/hdlc_cisco.c

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/*
* 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) {
printk(KERN_WARNING
"%s: Memory squeeze on cisco_keepalive_send()\n",
dev->name);
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)) {
printk(KERN_INFO "%s: Invalid length of Cisco control"
" packet (%d bytes)\n", dev->name, 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:
printk(KERN_INFO "%s: Unexpected Cisco IP address "
"reply\n", dev->name);
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;
printk(KERN_INFO "%s: Link up (peer "
"uptime %ud%uh%um%us)\n",
dev->name, 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) */
printk(KERN_INFO "%s: Unsupported protocol %x\n", dev->name,
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;
printk(KERN_INFO "%s: Link down\n", dev->name);
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");