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