linux/drivers/net/wan/syncppp.c
David S. Miller babcda74e9 drivers/net: Kill now superfluous ->last_rx stores.
The generic packet receive code takes care of setting
netdev->last_rx when necessary, for the sake of the
bonding ARP monitor.

Drivers need not do it any more.

Some cases had to be skipped over because the drivers
were making use of the ->last_rx value themselves.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-03 21:11:17 -08:00

1477 lines
39 KiB
C

/*
* NET3: A (fairly minimal) implementation of synchronous PPP for Linux
* as well as a CISCO HDLC implementation. See the copyright
* message below for the original source.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the license, or (at your option) any later version.
*
* Note however. This code is also used in a different form by FreeBSD.
* Therefore when making any non OS specific change please consider
* contributing it back to the original author under the terms
* below in addition.
* -- Alan
*
* Port for Linux-2.1 by Jan "Yenya" Kasprzak <kas@fi.muni.cz>
*/
/*
* Synchronous PPP/Cisco link level subroutines.
* Keepalive protocol implemented in both Cisco and PPP modes.
*
* Copyright (C) 1994 Cronyx Ltd.
* Author: Serge Vakulenko, <vak@zebub.msk.su>
*
* This software is distributed with NO WARRANTIES, not even the implied
* warranties for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
* Authors grant any other persons or organisations permission to use
* or modify this software as long as this message is kept with the software,
* all derivative works or modified versions.
*
* Version 1.9, Wed Oct 4 18:58:15 MSK 1995
*
* $Id: syncppp.c,v 1.18 2000/04/11 05:25:31 asj Exp $
*/
#undef DEBUG
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <linux/route.h>
#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <linux/random.h>
#include <linux/pkt_sched.h>
#include <linux/spinlock.h>
#include <linux/rcupdate.h>
#include <net/net_namespace.h>
#include <net/syncppp.h>
#include <asm/byteorder.h>
#include <asm/uaccess.h>
#define MAXALIVECNT 6 /* max. alive packets */
#define PPP_ALLSTATIONS 0xff /* All-Stations broadcast address */
#define PPP_UI 0x03 /* Unnumbered Information */
#define PPP_IP 0x0021 /* Internet Protocol */
#define PPP_ISO 0x0023 /* ISO OSI Protocol */
#define PPP_XNS 0x0025 /* Xerox NS Protocol */
#define PPP_IPX 0x002b /* Novell IPX Protocol */
#define PPP_LCP 0xc021 /* Link Control Protocol */
#define PPP_IPCP 0x8021 /* Internet Protocol Control Protocol */
#define LCP_CONF_REQ 1 /* PPP LCP configure request */
#define LCP_CONF_ACK 2 /* PPP LCP configure acknowledge */
#define LCP_CONF_NAK 3 /* PPP LCP configure negative ack */
#define LCP_CONF_REJ 4 /* PPP LCP configure reject */
#define LCP_TERM_REQ 5 /* PPP LCP terminate request */
#define LCP_TERM_ACK 6 /* PPP LCP terminate acknowledge */
#define LCP_CODE_REJ 7 /* PPP LCP code reject */
#define LCP_PROTO_REJ 8 /* PPP LCP protocol reject */
#define LCP_ECHO_REQ 9 /* PPP LCP echo request */
#define LCP_ECHO_REPLY 10 /* PPP LCP echo reply */
#define LCP_DISC_REQ 11 /* PPP LCP discard request */
#define LCP_OPT_MRU 1 /* maximum receive unit */
#define LCP_OPT_ASYNC_MAP 2 /* async control character map */
#define LCP_OPT_AUTH_PROTO 3 /* authentication protocol */
#define LCP_OPT_QUAL_PROTO 4 /* quality protocol */
#define LCP_OPT_MAGIC 5 /* magic number */
#define LCP_OPT_RESERVED 6 /* reserved */
#define LCP_OPT_PROTO_COMP 7 /* protocol field compression */
#define LCP_OPT_ADDR_COMP 8 /* address/control field compression */
#define IPCP_CONF_REQ LCP_CONF_REQ /* PPP IPCP configure request */
#define IPCP_CONF_ACK LCP_CONF_ACK /* PPP IPCP configure acknowledge */
#define IPCP_CONF_NAK LCP_CONF_NAK /* PPP IPCP configure negative ack */
#define IPCP_CONF_REJ LCP_CONF_REJ /* PPP IPCP configure reject */
#define IPCP_TERM_REQ LCP_TERM_REQ /* PPP IPCP terminate request */
#define IPCP_TERM_ACK LCP_TERM_ACK /* PPP IPCP terminate acknowledge */
#define IPCP_CODE_REJ LCP_CODE_REJ /* PPP IPCP code reject */
#define CISCO_MULTICAST 0x8f /* Cisco multicast address */
#define CISCO_UNICAST 0x0f /* Cisco unicast address */
#define CISCO_KEEPALIVE 0x8035 /* Cisco keepalive protocol */
#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 ppp_header {
u8 address;
u8 control;
__be16 protocol;
};
#define PPP_HEADER_LEN sizeof (struct ppp_header)
struct lcp_header {
u8 type;
u8 ident;
__be16 len;
};
#define LCP_HEADER_LEN sizeof (struct lcp_header)
struct cisco_packet {
__be32 type;
__be32 par1;
__be32 par2;
__be16 rel;
__be16 time0;
__be16 time1;
};
#define CISCO_PACKET_LEN 18
#define CISCO_BIG_PACKET_LEN 20
static struct sppp *spppq;
static struct timer_list sppp_keepalive_timer;
static DEFINE_SPINLOCK(spppq_lock);
/* global xmit queue for sending packets while spinlock is held */
static struct sk_buff_head tx_queue;
static void sppp_keepalive (unsigned long dummy);
static void sppp_cp_send (struct sppp *sp, u16 proto, u8 type,
u8 ident, u16 len, void *data);
static void sppp_cisco_send (struct sppp *sp, int type, u32 par1, u32 par2);
static void sppp_lcp_input (struct sppp *sp, struct sk_buff *m);
static void sppp_cisco_input (struct sppp *sp, struct sk_buff *m);
static void sppp_ipcp_input (struct sppp *sp, struct sk_buff *m);
static void sppp_lcp_open (struct sppp *sp);
static void sppp_ipcp_open (struct sppp *sp);
static int sppp_lcp_conf_parse_options (struct sppp *sp, struct lcp_header *h,
int len, u32 *magic);
static void sppp_cp_timeout (unsigned long arg);
static char *sppp_lcp_type_name (u8 type);
static char *sppp_ipcp_type_name (u8 type);
static void sppp_print_bytes (u8 *p, u16 len);
static int debug;
/* Flush global outgoing packet queue to dev_queue_xmit().
*
* dev_queue_xmit() must be called with interrupts enabled
* which means it can't be called with spinlocks held.
* If a packet needs to be sent while a spinlock is held,
* then put the packet into tx_queue, and call sppp_flush_xmit()
* after spinlock is released.
*/
static void sppp_flush_xmit(void)
{
struct sk_buff *skb;
while ((skb = skb_dequeue(&tx_queue)) != NULL)
dev_queue_xmit(skb);
}
/*
* Interface down stub
*/
static void if_down(struct net_device *dev)
{
struct sppp *sp = (struct sppp *)sppp_of(dev);
sp->pp_link_state=SPPP_LINK_DOWN;
}
/*
* Timeout routine activations.
*/
static void sppp_set_timeout(struct sppp *p,int s)
{
if (! (p->pp_flags & PP_TIMO))
{
init_timer(&p->pp_timer);
p->pp_timer.function=sppp_cp_timeout;
p->pp_timer.expires=jiffies+s*HZ;
p->pp_timer.data=(unsigned long)p;
p->pp_flags |= PP_TIMO;
add_timer(&p->pp_timer);
}
}
static void sppp_clear_timeout(struct sppp *p)
{
if (p->pp_flags & PP_TIMO)
{
del_timer(&p->pp_timer);
p->pp_flags &= ~PP_TIMO;
}
}
/**
* sppp_input - receive and process a WAN PPP frame
* @skb: The buffer to process
* @dev: The device it arrived on
*
* This can be called directly by cards that do not have
* timing constraints but is normally called from the network layer
* after interrupt servicing to process frames queued via netif_rx().
*
* We process the options in the card. If the frame is destined for
* the protocol stacks then it requeues the frame for the upper level
* protocol. If it is a control from it is processed and discarded
* here.
*/
static void sppp_input (struct net_device *dev, struct sk_buff *skb)
{
struct ppp_header *h;
struct sppp *sp = (struct sppp *)sppp_of(dev);
unsigned long flags;
skb->dev=dev;
skb_reset_mac_header(skb);
if (!pskb_may_pull(skb, PPP_HEADER_LEN)) {
/* Too small packet, drop it. */
if (sp->pp_flags & PP_DEBUG)
printk (KERN_DEBUG "%s: input packet is too small, %d bytes\n",
dev->name, skb->len);
kfree_skb(skb);
return;
}
/* Get PPP header. */
h = (struct ppp_header *)skb->data;
skb_pull(skb,sizeof(struct ppp_header));
spin_lock_irqsave(&sp->lock, flags);
switch (h->address) {
default: /* Invalid PPP packet. */
goto invalid;
case PPP_ALLSTATIONS:
if (h->control != PPP_UI)
goto invalid;
if (sp->pp_flags & PP_CISCO) {
if (sp->pp_flags & PP_DEBUG)
printk (KERN_WARNING "%s: PPP packet in Cisco mode <0x%x 0x%x 0x%x>\n",
dev->name,
h->address, h->control, ntohs (h->protocol));
goto drop;
}
switch (ntohs (h->protocol)) {
default:
if (sp->lcp.state == LCP_STATE_OPENED)
sppp_cp_send (sp, PPP_LCP, LCP_PROTO_REJ,
++sp->pp_seq, skb->len + 2,
&h->protocol);
if (sp->pp_flags & PP_DEBUG)
printk (KERN_WARNING "%s: invalid input protocol <0x%x 0x%x 0x%x>\n",
dev->name,
h->address, h->control, ntohs (h->protocol));
goto drop;
case PPP_LCP:
sppp_lcp_input (sp, skb);
goto drop;
case PPP_IPCP:
if (sp->lcp.state == LCP_STATE_OPENED)
sppp_ipcp_input (sp, skb);
else
printk(KERN_DEBUG "IPCP when still waiting LCP finish.\n");
goto drop;
case PPP_IP:
if (sp->ipcp.state == IPCP_STATE_OPENED) {
if(sp->pp_flags&PP_DEBUG)
printk(KERN_DEBUG "Yow an IP frame.\n");
skb->protocol=htons(ETH_P_IP);
netif_rx(skb);
goto done;
}
break;
#ifdef IPX
case PPP_IPX:
/* IPX IPXCP not implemented yet */
if (sp->lcp.state == LCP_STATE_OPENED) {
skb->protocol=htons(ETH_P_IPX);
netif_rx(skb);
goto done;
}
break;
#endif
}
break;
case CISCO_MULTICAST:
case CISCO_UNICAST:
/* Don't check the control field here (RFC 1547). */
if (! (sp->pp_flags & PP_CISCO)) {
if (sp->pp_flags & PP_DEBUG)
printk (KERN_WARNING "%s: Cisco packet in PPP mode <0x%x 0x%x 0x%x>\n",
dev->name,
h->address, h->control, ntohs (h->protocol));
goto drop;
}
switch (ntohs (h->protocol)) {
default:
goto invalid;
case CISCO_KEEPALIVE:
sppp_cisco_input (sp, skb);
goto drop;
#ifdef CONFIG_INET
case ETH_P_IP:
skb->protocol=htons(ETH_P_IP);
netif_rx(skb);
goto done;
#endif
#ifdef CONFIG_IPX
case ETH_P_IPX:
skb->protocol=htons(ETH_P_IPX);
netif_rx(skb);
goto done;
#endif
}
break;
}
goto drop;
invalid:
if (sp->pp_flags & PP_DEBUG)
printk (KERN_WARNING "%s: invalid input packet <0x%x 0x%x 0x%x>\n",
dev->name, h->address, h->control, ntohs (h->protocol));
drop:
kfree_skb(skb);
done:
spin_unlock_irqrestore(&sp->lock, flags);
sppp_flush_xmit();
return;
}
/*
* Handle transmit packets.
*/
static int sppp_hard_header(struct sk_buff *skb,
struct net_device *dev, __u16 type,
const void *daddr, const void *saddr,
unsigned int len)
{
struct sppp *sp = (struct sppp *)sppp_of(dev);
struct ppp_header *h;
skb_push(skb,sizeof(struct ppp_header));
h=(struct ppp_header *)skb->data;
if(sp->pp_flags&PP_CISCO)
{
h->address = CISCO_UNICAST;
h->control = 0;
}
else
{
h->address = PPP_ALLSTATIONS;
h->control = PPP_UI;
}
if(sp->pp_flags & PP_CISCO)
{
h->protocol = htons(type);
}
else switch(type)
{
case ETH_P_IP:
h->protocol = htons(PPP_IP);
break;
case ETH_P_IPX:
h->protocol = htons(PPP_IPX);
break;
}
return sizeof(struct ppp_header);
}
static const struct header_ops sppp_header_ops = {
.create = sppp_hard_header,
};
/*
* Send keepalive packets, every 10 seconds.
*/
static void sppp_keepalive (unsigned long dummy)
{
struct sppp *sp;
unsigned long flags;
spin_lock_irqsave(&spppq_lock, flags);
for (sp=spppq; sp; sp=sp->pp_next)
{
struct net_device *dev = sp->pp_if;
/* Keepalive mode disabled or channel down? */
if (! (sp->pp_flags & PP_KEEPALIVE) ||
! (dev->flags & IFF_UP))
continue;
spin_lock(&sp->lock);
/* No keepalive in PPP mode if LCP not opened yet. */
if (! (sp->pp_flags & PP_CISCO) &&
sp->lcp.state != LCP_STATE_OPENED) {
spin_unlock(&sp->lock);
continue;
}
if (sp->pp_alivecnt == MAXALIVECNT) {
/* No keepalive packets got. Stop the interface. */
printk (KERN_WARNING "%s: protocol down\n", dev->name);
if_down (dev);
if (! (sp->pp_flags & PP_CISCO)) {
/* Shut down the PPP link. */
sp->lcp.magic = jiffies;
sp->lcp.state = LCP_STATE_CLOSED;
sp->ipcp.state = IPCP_STATE_CLOSED;
sppp_clear_timeout (sp);
/* Initiate negotiation. */
sppp_lcp_open (sp);
}
}
if (sp->pp_alivecnt <= MAXALIVECNT)
++sp->pp_alivecnt;
if (sp->pp_flags & PP_CISCO)
sppp_cisco_send (sp, CISCO_KEEPALIVE_REQ, ++sp->pp_seq,
sp->pp_rseq);
else if (sp->lcp.state == LCP_STATE_OPENED) {
__be32 nmagic = htonl (sp->lcp.magic);
sp->lcp.echoid = ++sp->pp_seq;
sppp_cp_send (sp, PPP_LCP, LCP_ECHO_REQ,
sp->lcp.echoid, 4, &nmagic);
}
spin_unlock(&sp->lock);
}
spin_unlock_irqrestore(&spppq_lock, flags);
sppp_flush_xmit();
sppp_keepalive_timer.expires=jiffies+10*HZ;
add_timer(&sppp_keepalive_timer);
}
/*
* Handle incoming PPP Link Control Protocol packets.
*/
static void sppp_lcp_input (struct sppp *sp, struct sk_buff *skb)
{
struct lcp_header *h;
struct net_device *dev = sp->pp_if;
int len = skb->len;
u8 *p, opt[6];
u32 rmagic = 0;
if (!pskb_may_pull(skb, sizeof(struct lcp_header))) {
if (sp->pp_flags & PP_DEBUG)
printk (KERN_WARNING "%s: invalid lcp packet length: %d bytes\n",
dev->name, len);
return;
}
h = (struct lcp_header *)skb->data;
skb_pull(skb,sizeof(struct lcp_header *));
if (sp->pp_flags & PP_DEBUG)
{
char state = '?';
switch (sp->lcp.state) {
case LCP_STATE_CLOSED: state = 'C'; break;
case LCP_STATE_ACK_RCVD: state = 'R'; break;
case LCP_STATE_ACK_SENT: state = 'S'; break;
case LCP_STATE_OPENED: state = 'O'; break;
}
printk (KERN_WARNING "%s: lcp input(%c): %d bytes <%s id=%xh len=%xh",
dev->name, state, len,
sppp_lcp_type_name (h->type), h->ident, ntohs (h->len));
if (len > 4)
sppp_print_bytes ((u8*) (h+1), len-4);
printk (">\n");
}
if (len > ntohs (h->len))
len = ntohs (h->len);
switch (h->type) {
default:
/* Unknown packet type -- send Code-Reject packet. */
sppp_cp_send (sp, PPP_LCP, LCP_CODE_REJ, ++sp->pp_seq,
skb->len, h);
break;
case LCP_CONF_REQ:
if (len < 4) {
if (sp->pp_flags & PP_DEBUG)
printk (KERN_DEBUG"%s: invalid lcp configure request packet length: %d bytes\n",
dev->name, len);
break;
}
if (len>4 && !sppp_lcp_conf_parse_options (sp, h, len, &rmagic))
goto badreq;
if (rmagic == sp->lcp.magic) {
/* Local and remote magics equal -- loopback? */
if (sp->pp_loopcnt >= MAXALIVECNT*5) {
printk (KERN_WARNING "%s: loopback\n",
dev->name);
sp->pp_loopcnt = 0;
if (dev->flags & IFF_UP) {
if_down (dev);
}
} else if (sp->pp_flags & PP_DEBUG)
printk (KERN_DEBUG "%s: conf req: magic glitch\n",
dev->name);
++sp->pp_loopcnt;
/* MUST send Conf-Nack packet. */
rmagic = ~sp->lcp.magic;
opt[0] = LCP_OPT_MAGIC;
opt[1] = sizeof (opt);
opt[2] = rmagic >> 24;
opt[3] = rmagic >> 16;
opt[4] = rmagic >> 8;
opt[5] = rmagic;
sppp_cp_send (sp, PPP_LCP, LCP_CONF_NAK,
h->ident, sizeof (opt), &opt);
badreq:
switch (sp->lcp.state) {
case LCP_STATE_OPENED:
/* Initiate renegotiation. */
sppp_lcp_open (sp);
/* fall through... */
case LCP_STATE_ACK_SENT:
/* Go to closed state. */
sp->lcp.state = LCP_STATE_CLOSED;
sp->ipcp.state = IPCP_STATE_CLOSED;
}
break;
}
/* Send Configure-Ack packet. */
sp->pp_loopcnt = 0;
if (sp->lcp.state != LCP_STATE_OPENED) {
sppp_cp_send (sp, PPP_LCP, LCP_CONF_ACK,
h->ident, len-4, h+1);
}
/* Change the state. */
switch (sp->lcp.state) {
case LCP_STATE_CLOSED:
sp->lcp.state = LCP_STATE_ACK_SENT;
break;
case LCP_STATE_ACK_RCVD:
sp->lcp.state = LCP_STATE_OPENED;
sppp_ipcp_open (sp);
break;
case LCP_STATE_OPENED:
/* Remote magic changed -- close session. */
sp->lcp.state = LCP_STATE_CLOSED;
sp->ipcp.state = IPCP_STATE_CLOSED;
/* Initiate renegotiation. */
sppp_lcp_open (sp);
/* Send ACK after our REQ in attempt to break loop */
sppp_cp_send (sp, PPP_LCP, LCP_CONF_ACK,
h->ident, len-4, h+1);
sp->lcp.state = LCP_STATE_ACK_SENT;
break;
}
break;
case LCP_CONF_ACK:
if (h->ident != sp->lcp.confid)
break;
sppp_clear_timeout (sp);
if ((sp->pp_link_state != SPPP_LINK_UP) &&
(dev->flags & IFF_UP)) {
/* Coming out of loopback mode. */
sp->pp_link_state=SPPP_LINK_UP;
printk (KERN_INFO "%s: protocol up\n", dev->name);
}
switch (sp->lcp.state) {
case LCP_STATE_CLOSED:
sp->lcp.state = LCP_STATE_ACK_RCVD;
sppp_set_timeout (sp, 5);
break;
case LCP_STATE_ACK_SENT:
sp->lcp.state = LCP_STATE_OPENED;
sppp_ipcp_open (sp);
break;
}
break;
case LCP_CONF_NAK:
if (h->ident != sp->lcp.confid)
break;
p = (u8*) (h+1);
if (len>=10 && p[0] == LCP_OPT_MAGIC && p[1] >= 4) {
rmagic = (u32)p[2] << 24 |
(u32)p[3] << 16 | p[4] << 8 | p[5];
if (rmagic == ~sp->lcp.magic) {
int newmagic;
if (sp->pp_flags & PP_DEBUG)
printk (KERN_DEBUG "%s: conf nak: magic glitch\n",
dev->name);
get_random_bytes(&newmagic, sizeof(newmagic));
sp->lcp.magic += newmagic;
} else
sp->lcp.magic = rmagic;
}
if (sp->lcp.state != LCP_STATE_ACK_SENT) {
/* Go to closed state. */
sp->lcp.state = LCP_STATE_CLOSED;
sp->ipcp.state = IPCP_STATE_CLOSED;
}
/* The link will be renegotiated after timeout,
* to avoid endless req-nack loop. */
sppp_clear_timeout (sp);
sppp_set_timeout (sp, 2);
break;
case LCP_CONF_REJ:
if (h->ident != sp->lcp.confid)
break;
sppp_clear_timeout (sp);
/* Initiate renegotiation. */
sppp_lcp_open (sp);
if (sp->lcp.state != LCP_STATE_ACK_SENT) {
/* Go to closed state. */
sp->lcp.state = LCP_STATE_CLOSED;
sp->ipcp.state = IPCP_STATE_CLOSED;
}
break;
case LCP_TERM_REQ:
sppp_clear_timeout (sp);
/* Send Terminate-Ack packet. */
sppp_cp_send (sp, PPP_LCP, LCP_TERM_ACK, h->ident, 0, NULL);
/* Go to closed state. */
sp->lcp.state = LCP_STATE_CLOSED;
sp->ipcp.state = IPCP_STATE_CLOSED;
/* Initiate renegotiation. */
sppp_lcp_open (sp);
break;
case LCP_TERM_ACK:
case LCP_CODE_REJ:
case LCP_PROTO_REJ:
/* Ignore for now. */
break;
case LCP_DISC_REQ:
/* Discard the packet. */
break;
case LCP_ECHO_REQ:
if (sp->lcp.state != LCP_STATE_OPENED)
break;
if (len < 8) {
if (sp->pp_flags & PP_DEBUG)
printk (KERN_WARNING "%s: invalid lcp echo request packet length: %d bytes\n",
dev->name, len);
break;
}
if (ntohl (*(__be32*)(h+1)) == sp->lcp.magic) {
/* Line loopback mode detected. */
printk (KERN_WARNING "%s: loopback\n", dev->name);
if_down (dev);
/* Shut down the PPP link. */
sp->lcp.state = LCP_STATE_CLOSED;
sp->ipcp.state = IPCP_STATE_CLOSED;
sppp_clear_timeout (sp);
/* Initiate negotiation. */
sppp_lcp_open (sp);
break;
}
*(__be32 *)(h+1) = htonl (sp->lcp.magic);
sppp_cp_send (sp, PPP_LCP, LCP_ECHO_REPLY, h->ident, len-4, h+1);
break;
case LCP_ECHO_REPLY:
if (h->ident != sp->lcp.echoid)
break;
if (len < 8) {
if (sp->pp_flags & PP_DEBUG)
printk (KERN_WARNING "%s: invalid lcp echo reply packet length: %d bytes\n",
dev->name, len);
break;
}
if (ntohl(*(__be32 *)(h+1)) != sp->lcp.magic)
sp->pp_alivecnt = 0;
break;
}
}
/*
* Handle incoming Cisco keepalive protocol packets.
*/
static void sppp_cisco_input (struct sppp *sp, struct sk_buff *skb)
{
struct cisco_packet *h;
struct net_device *dev = sp->pp_if;
if (!pskb_may_pull(skb, sizeof(struct cisco_packet))
|| (skb->len != CISCO_PACKET_LEN
&& skb->len != CISCO_BIG_PACKET_LEN)) {
if (sp->pp_flags & PP_DEBUG)
printk (KERN_WARNING "%s: invalid cisco packet length: %d bytes\n",
dev->name, skb->len);
return;
}
h = (struct cisco_packet *)skb->data;
skb_pull(skb, sizeof(struct cisco_packet*));
if (sp->pp_flags & PP_DEBUG)
printk (KERN_WARNING "%s: cisco input: %d bytes <%xh %xh %xh %xh %xh-%xh>\n",
dev->name, skb->len,
ntohl (h->type), h->par1, h->par2, h->rel,
h->time0, h->time1);
switch (ntohl (h->type)) {
default:
if (sp->pp_flags & PP_DEBUG)
printk (KERN_WARNING "%s: unknown cisco packet type: 0x%x\n",
dev->name, ntohl (h->type));
break;
case CISCO_ADDR_REPLY:
/* Reply on address request, ignore */
break;
case CISCO_KEEPALIVE_REQ:
sp->pp_alivecnt = 0;
sp->pp_rseq = ntohl (h->par1);
if (sp->pp_seq == sp->pp_rseq) {
/* Local and remote sequence numbers are equal.
* Probably, the line is in loopback mode. */
int newseq;
if (sp->pp_loopcnt >= MAXALIVECNT) {
printk (KERN_WARNING "%s: loopback\n",
dev->name);
sp->pp_loopcnt = 0;
if (dev->flags & IFF_UP) {
if_down (dev);
}
}
++sp->pp_loopcnt;
/* Generate new local sequence number */
get_random_bytes(&newseq, sizeof(newseq));
sp->pp_seq ^= newseq;
break;
}
sp->pp_loopcnt = 0;
if (sp->pp_link_state==SPPP_LINK_DOWN &&
(dev->flags & IFF_UP)) {
sp->pp_link_state=SPPP_LINK_UP;
printk (KERN_INFO "%s: protocol up\n", dev->name);
}
break;
case CISCO_ADDR_REQ:
/* Stolen from net/ipv4/devinet.c -- SIOCGIFADDR ioctl */
{
__be32 addr = 0, mask = htonl(~0U); /* FIXME: is the mask correct? */
#ifdef CONFIG_INET
struct in_device *in_dev;
struct in_ifaddr *ifa;
rcu_read_lock();
if ((in_dev = __in_dev_get_rcu(dev)) != NULL)
{
for (ifa=in_dev->ifa_list; ifa != NULL;
ifa=ifa->ifa_next) {
if (strcmp(dev->name, ifa->ifa_label) == 0)
{
addr = ifa->ifa_local;
mask = ifa->ifa_mask;
break;
}
}
}
rcu_read_unlock();
#endif
sppp_cisco_send (sp, CISCO_ADDR_REPLY, ntohl(addr), ntohl(mask));
break;
}
}
}
/*
* Send PPP LCP packet.
*/
static void sppp_cp_send (struct sppp *sp, u16 proto, u8 type,
u8 ident, u16 len, void *data)
{
struct ppp_header *h;
struct lcp_header *lh;
struct sk_buff *skb;
struct net_device *dev = sp->pp_if;
skb=alloc_skb(dev->hard_header_len+PPP_HEADER_LEN+LCP_HEADER_LEN+len,
GFP_ATOMIC);
if (skb==NULL)
return;
skb_reserve(skb,dev->hard_header_len);
h = (struct ppp_header *)skb_put(skb, sizeof(struct ppp_header));
h->address = PPP_ALLSTATIONS; /* broadcast address */
h->control = PPP_UI; /* Unnumbered Info */
h->protocol = htons (proto); /* Link Control Protocol */
lh = (struct lcp_header *)skb_put(skb, sizeof(struct lcp_header));
lh->type = type;
lh->ident = ident;
lh->len = htons (LCP_HEADER_LEN + len);
if (len)
memcpy(skb_put(skb,len),data, len);
if (sp->pp_flags & PP_DEBUG) {
printk (KERN_WARNING "%s: %s output <%s id=%xh len=%xh",
dev->name,
proto==PPP_LCP ? "lcp" : "ipcp",
proto==PPP_LCP ? sppp_lcp_type_name (lh->type) :
sppp_ipcp_type_name (lh->type), lh->ident,
ntohs (lh->len));
if (len)
sppp_print_bytes ((u8*) (lh+1), len);
printk (">\n");
}
/* Control is high priority so it doesn't get queued behind data */
skb->priority=TC_PRIO_CONTROL;
skb->dev = dev;
skb_queue_tail(&tx_queue, skb);
}
/*
* Send Cisco keepalive packet.
*/
static void sppp_cisco_send (struct sppp *sp, int type, u32 par1, u32 par2)
{
struct ppp_header *h;
struct cisco_packet *ch;
struct sk_buff *skb;
struct net_device *dev = sp->pp_if;
u32 t = jiffies * 1000/HZ;
skb=alloc_skb(dev->hard_header_len+PPP_HEADER_LEN+CISCO_PACKET_LEN,
GFP_ATOMIC);
if(skb==NULL)
return;
skb_reserve(skb, dev->hard_header_len);
h = (struct ppp_header *)skb_put (skb, sizeof(struct ppp_header));
h->address = CISCO_MULTICAST;
h->control = 0;
h->protocol = htons (CISCO_KEEPALIVE);
ch = (struct cisco_packet*)skb_put(skb, CISCO_PACKET_LEN);
ch->type = htonl (type);
ch->par1 = htonl (par1);
ch->par2 = htonl (par2);
ch->rel = htons(0xffff);
ch->time0 = htons ((u16) (t >> 16));
ch->time1 = htons ((u16) t);
if (sp->pp_flags & PP_DEBUG)
printk (KERN_WARNING "%s: cisco output: <%xh %xh %xh %xh %xh-%xh>\n",
dev->name, ntohl (ch->type), ch->par1,
ch->par2, ch->rel, ch->time0, ch->time1);
skb->priority=TC_PRIO_CONTROL;
skb->dev = dev;
skb_queue_tail(&tx_queue, skb);
}
/**
* sppp_close - close down a synchronous PPP or Cisco HDLC link
* @dev: The network device to drop the link of
*
* This drops the logical interface to the channel. It is not
* done politely as we assume we will also be dropping DTR. Any
* timeouts are killed.
*/
int sppp_close (struct net_device *dev)
{
struct sppp *sp = (struct sppp *)sppp_of(dev);
unsigned long flags;
spin_lock_irqsave(&sp->lock, flags);
sp->pp_link_state = SPPP_LINK_DOWN;
sp->lcp.state = LCP_STATE_CLOSED;
sp->ipcp.state = IPCP_STATE_CLOSED;
sppp_clear_timeout (sp);
spin_unlock_irqrestore(&sp->lock, flags);
return 0;
}
EXPORT_SYMBOL(sppp_close);
/**
* sppp_open - open a synchronous PPP or Cisco HDLC link
* @dev: Network device to activate
*
* Close down any existing synchronous session and commence
* from scratch. In the PPP case this means negotiating LCP/IPCP
* and friends, while for Cisco HDLC we simply need to start sending
* keepalives
*/
int sppp_open (struct net_device *dev)
{
struct sppp *sp = (struct sppp *)sppp_of(dev);
unsigned long flags;
sppp_close(dev);
spin_lock_irqsave(&sp->lock, flags);
if (!(sp->pp_flags & PP_CISCO)) {
sppp_lcp_open (sp);
}
sp->pp_link_state = SPPP_LINK_DOWN;
spin_unlock_irqrestore(&sp->lock, flags);
sppp_flush_xmit();
return 0;
}
EXPORT_SYMBOL(sppp_open);
/**
* sppp_reopen - notify of physical link loss
* @dev: Device that lost the link
*
* This function informs the synchronous protocol code that
* the underlying link died (for example a carrier drop on X.21)
*
* We increment the magic numbers to ensure that if the other end
* failed to notice we will correctly start a new session. It happens
* do to the nature of telco circuits is that you can lose carrier on
* one endonly.
*
* Having done this we go back to negotiating. This function may
* be called from an interrupt context.
*/
int sppp_reopen (struct net_device *dev)
{
struct sppp *sp = (struct sppp *)sppp_of(dev);
unsigned long flags;
sppp_close(dev);
spin_lock_irqsave(&sp->lock, flags);
if (!(sp->pp_flags & PP_CISCO))
{
sp->lcp.magic = jiffies;
++sp->pp_seq;
sp->lcp.state = LCP_STATE_CLOSED;
sp->ipcp.state = IPCP_STATE_CLOSED;
/* Give it a moment for the line to settle then go */
sppp_set_timeout (sp, 1);
}
sp->pp_link_state=SPPP_LINK_DOWN;
spin_unlock_irqrestore(&sp->lock, flags);
return 0;
}
EXPORT_SYMBOL(sppp_reopen);
/**
* sppp_change_mtu - Change the link MTU
* @dev: Device to change MTU on
* @new_mtu: New MTU
*
* Change the MTU on the link. This can only be called with
* the link down. It returns an error if the link is up or
* the mtu is out of range.
*/
static int sppp_change_mtu(struct net_device *dev, int new_mtu)
{
if(new_mtu<128||new_mtu>PPP_MTU||(dev->flags&IFF_UP))
return -EINVAL;
dev->mtu=new_mtu;
return 0;
}
/**
* sppp_do_ioctl - Ioctl handler for ppp/hdlc
* @dev: Device subject to ioctl
* @ifr: Interface request block from the user
* @cmd: Command that is being issued
*
* This function handles the ioctls that may be issued by the user
* to control the settings of a PPP/HDLC link. It does both busy
* and security checks. This function is intended to be wrapped by
* callers who wish to add additional ioctl calls of their own.
*/
int sppp_do_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
struct sppp *sp = (struct sppp *)sppp_of(dev);
if(dev->flags&IFF_UP)
return -EBUSY;
if(!capable(CAP_NET_ADMIN))
return -EPERM;
switch(cmd)
{
case SPPPIOCCISCO:
sp->pp_flags|=PP_CISCO;
dev->type = ARPHRD_HDLC;
break;
case SPPPIOCPPP:
sp->pp_flags&=~PP_CISCO;
dev->type = ARPHRD_PPP;
break;
case SPPPIOCDEBUG:
sp->pp_flags&=~PP_DEBUG;
if(ifr->ifr_flags)
sp->pp_flags|=PP_DEBUG;
break;
case SPPPIOCGFLAGS:
if(copy_to_user(ifr->ifr_data, &sp->pp_flags, sizeof(sp->pp_flags)))
return -EFAULT;
break;
case SPPPIOCSFLAGS:
if(copy_from_user(&sp->pp_flags, ifr->ifr_data, sizeof(sp->pp_flags)))
return -EFAULT;
break;
default:
return -EINVAL;
}
return 0;
}
EXPORT_SYMBOL(sppp_do_ioctl);
/**
* sppp_attach - attach synchronous PPP/HDLC to a device
* @pd: PPP device to initialise
*
* This initialises the PPP/HDLC support on an interface. At the
* time of calling the dev element must point to the network device
* that this interface is attached to. The interface should not yet
* be registered.
*/
void sppp_attach(struct ppp_device *pd)
{
struct net_device *dev = pd->dev;
struct sppp *sp = &pd->sppp;
unsigned long flags;
/* Make sure embedding is safe for sppp_of */
BUG_ON(sppp_of(dev) != sp);
spin_lock_irqsave(&spppq_lock, flags);
/* Initialize keepalive handler. */
if (! spppq)
{
init_timer(&sppp_keepalive_timer);
sppp_keepalive_timer.expires=jiffies+10*HZ;
sppp_keepalive_timer.function=sppp_keepalive;
add_timer(&sppp_keepalive_timer);
}
/* Insert new entry into the keepalive list. */
sp->pp_next = spppq;
spppq = sp;
spin_unlock_irqrestore(&spppq_lock, flags);
sp->pp_loopcnt = 0;
sp->pp_alivecnt = 0;
sp->pp_seq = 0;
sp->pp_rseq = 0;
sp->pp_flags = PP_KEEPALIVE|PP_CISCO|debug;/*PP_DEBUG;*/
sp->lcp.magic = 0;
sp->lcp.state = LCP_STATE_CLOSED;
sp->ipcp.state = IPCP_STATE_CLOSED;
sp->pp_if = dev;
spin_lock_init(&sp->lock);
/*
* Device specific setup. All but interrupt handler and
* hard_start_xmit.
*/
dev->header_ops = &sppp_header_ops;
dev->tx_queue_len = 10;
dev->type = ARPHRD_HDLC;
dev->addr_len = 0;
dev->hard_header_len = sizeof(struct ppp_header);
dev->mtu = PPP_MTU;
/*
* These 4 are callers but MUST also call sppp_ functions
*/
dev->do_ioctl = sppp_do_ioctl;
#if 0
dev->get_stats = NULL; /* Let the driver override these */
dev->open = sppp_open;
dev->stop = sppp_close;
#endif
dev->change_mtu = sppp_change_mtu;
dev->flags = IFF_MULTICAST|IFF_POINTOPOINT|IFF_NOARP;
}
EXPORT_SYMBOL(sppp_attach);
/**
* sppp_detach - release PPP resources from a device
* @dev: Network device to release
*
* Stop and free up any PPP/HDLC resources used by this
* interface. This must be called before the device is
* freed.
*/
void sppp_detach (struct net_device *dev)
{
struct sppp **q, *p, *sp = (struct sppp *)sppp_of(dev);
unsigned long flags;
spin_lock_irqsave(&spppq_lock, flags);
/* Remove the entry from the keepalive list. */
for (q = &spppq; (p = *q); q = &p->pp_next)
if (p == sp) {
*q = p->pp_next;
break;
}
/* Stop keepalive handler. */
if (! spppq)
del_timer(&sppp_keepalive_timer);
sppp_clear_timeout (sp);
spin_unlock_irqrestore(&spppq_lock, flags);
}
EXPORT_SYMBOL(sppp_detach);
/*
* Analyze the LCP Configure-Request options list
* for the presence of unknown options.
* If the request contains unknown options, build and
* send Configure-reject packet, containing only unknown options.
*/
static int
sppp_lcp_conf_parse_options (struct sppp *sp, struct lcp_header *h,
int len, u32 *magic)
{
u8 *buf, *r, *p;
int rlen;
len -= 4;
buf = r = kmalloc (len, GFP_ATOMIC);
if (! buf)
return (0);
p = (void*) (h+1);
for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
switch (*p) {
case LCP_OPT_MAGIC:
/* Magic number -- extract. */
if (len >= 6 && p[1] == 6) {
*magic = (u32)p[2] << 24 |
(u32)p[3] << 16 | p[4] << 8 | p[5];
continue;
}
break;
case LCP_OPT_ASYNC_MAP:
/* Async control character map -- check to be zero. */
if (len >= 6 && p[1] == 6 && ! p[2] && ! p[3] &&
! p[4] && ! p[5])
continue;
break;
case LCP_OPT_MRU:
/* Maximum receive unit -- always OK. */
continue;
default:
/* Others not supported. */
break;
}
/* Add the option to rejected list. */
memcpy(r, p, p[1]);
r += p[1];
rlen += p[1];
}
if (rlen)
sppp_cp_send (sp, PPP_LCP, LCP_CONF_REJ, h->ident, rlen, buf);
kfree(buf);
return (rlen == 0);
}
static void sppp_ipcp_input (struct sppp *sp, struct sk_buff *skb)
{
struct lcp_header *h;
struct net_device *dev = sp->pp_if;
int len = skb->len;
if (!pskb_may_pull(skb, sizeof(struct lcp_header))) {
if (sp->pp_flags & PP_DEBUG)
printk (KERN_WARNING "%s: invalid ipcp packet length: %d bytes\n",
dev->name, len);
return;
}
h = (struct lcp_header *)skb->data;
skb_pull(skb,sizeof(struct lcp_header));
if (sp->pp_flags & PP_DEBUG) {
printk (KERN_WARNING "%s: ipcp input: %d bytes <%s id=%xh len=%xh",
dev->name, len,
sppp_ipcp_type_name (h->type), h->ident, ntohs (h->len));
if (len > 4)
sppp_print_bytes ((u8*) (h+1), len-4);
printk (">\n");
}
if (len > ntohs (h->len))
len = ntohs (h->len);
switch (h->type) {
default:
/* Unknown packet type -- send Code-Reject packet. */
sppp_cp_send (sp, PPP_IPCP, IPCP_CODE_REJ, ++sp->pp_seq, len, h);
break;
case IPCP_CONF_REQ:
if (len < 4) {
if (sp->pp_flags & PP_DEBUG)
printk (KERN_WARNING "%s: invalid ipcp configure request packet length: %d bytes\n",
dev->name, len);
return;
}
if (len > 4) {
sppp_cp_send (sp, PPP_IPCP, LCP_CONF_REJ, h->ident,
len-4, h+1);
switch (sp->ipcp.state) {
case IPCP_STATE_OPENED:
/* Initiate renegotiation. */
sppp_ipcp_open (sp);
/* fall through... */
case IPCP_STATE_ACK_SENT:
/* Go to closed state. */
sp->ipcp.state = IPCP_STATE_CLOSED;
}
} else {
/* Send Configure-Ack packet. */
sppp_cp_send (sp, PPP_IPCP, IPCP_CONF_ACK, h->ident,
0, NULL);
/* Change the state. */
if (sp->ipcp.state == IPCP_STATE_ACK_RCVD)
sp->ipcp.state = IPCP_STATE_OPENED;
else
sp->ipcp.state = IPCP_STATE_ACK_SENT;
}
break;
case IPCP_CONF_ACK:
if (h->ident != sp->ipcp.confid)
break;
sppp_clear_timeout (sp);
switch (sp->ipcp.state) {
case IPCP_STATE_CLOSED:
sp->ipcp.state = IPCP_STATE_ACK_RCVD;
sppp_set_timeout (sp, 5);
break;
case IPCP_STATE_ACK_SENT:
sp->ipcp.state = IPCP_STATE_OPENED;
break;
}
break;
case IPCP_CONF_NAK:
case IPCP_CONF_REJ:
if (h->ident != sp->ipcp.confid)
break;
sppp_clear_timeout (sp);
/* Initiate renegotiation. */
sppp_ipcp_open (sp);
if (sp->ipcp.state != IPCP_STATE_ACK_SENT)
/* Go to closed state. */
sp->ipcp.state = IPCP_STATE_CLOSED;
break;
case IPCP_TERM_REQ:
/* Send Terminate-Ack packet. */
sppp_cp_send (sp, PPP_IPCP, IPCP_TERM_ACK, h->ident, 0, NULL);
/* Go to closed state. */
sp->ipcp.state = IPCP_STATE_CLOSED;
/* Initiate renegotiation. */
sppp_ipcp_open (sp);
break;
case IPCP_TERM_ACK:
/* Ignore for now. */
case IPCP_CODE_REJ:
/* Ignore for now. */
break;
}
}
static void sppp_lcp_open (struct sppp *sp)
{
char opt[6];
if (! sp->lcp.magic)
sp->lcp.magic = jiffies;
opt[0] = LCP_OPT_MAGIC;
opt[1] = sizeof (opt);
opt[2] = sp->lcp.magic >> 24;
opt[3] = sp->lcp.magic >> 16;
opt[4] = sp->lcp.magic >> 8;
opt[5] = sp->lcp.magic;
sp->lcp.confid = ++sp->pp_seq;
sppp_cp_send (sp, PPP_LCP, LCP_CONF_REQ, sp->lcp.confid,
sizeof (opt), &opt);
sppp_set_timeout (sp, 2);
}
static void sppp_ipcp_open (struct sppp *sp)
{
sp->ipcp.confid = ++sp->pp_seq;
sppp_cp_send (sp, PPP_IPCP, IPCP_CONF_REQ, sp->ipcp.confid, 0, NULL);
sppp_set_timeout (sp, 2);
}
/*
* Process PPP control protocol timeouts.
*/
static void sppp_cp_timeout (unsigned long arg)
{
struct sppp *sp = (struct sppp*) arg;
unsigned long flags;
spin_lock_irqsave(&sp->lock, flags);
sp->pp_flags &= ~PP_TIMO;
if (! (sp->pp_if->flags & IFF_UP) || (sp->pp_flags & PP_CISCO)) {
spin_unlock_irqrestore(&sp->lock, flags);
return;
}
switch (sp->lcp.state) {
case LCP_STATE_CLOSED:
/* No ACK for Configure-Request, retry. */
sppp_lcp_open (sp);
break;
case LCP_STATE_ACK_RCVD:
/* ACK got, but no Configure-Request for peer, retry. */
sppp_lcp_open (sp);
sp->lcp.state = LCP_STATE_CLOSED;
break;
case LCP_STATE_ACK_SENT:
/* ACK sent but no ACK for Configure-Request, retry. */
sppp_lcp_open (sp);
break;
case LCP_STATE_OPENED:
/* LCP is already OK, try IPCP. */
switch (sp->ipcp.state) {
case IPCP_STATE_CLOSED:
/* No ACK for Configure-Request, retry. */
sppp_ipcp_open (sp);
break;
case IPCP_STATE_ACK_RCVD:
/* ACK got, but no Configure-Request for peer, retry. */
sppp_ipcp_open (sp);
sp->ipcp.state = IPCP_STATE_CLOSED;
break;
case IPCP_STATE_ACK_SENT:
/* ACK sent but no ACK for Configure-Request, retry. */
sppp_ipcp_open (sp);
break;
case IPCP_STATE_OPENED:
/* IPCP is OK. */
break;
}
break;
}
spin_unlock_irqrestore(&sp->lock, flags);
sppp_flush_xmit();
}
static char *sppp_lcp_type_name (u8 type)
{
static char buf [8];
switch (type) {
case LCP_CONF_REQ: return ("conf-req");
case LCP_CONF_ACK: return ("conf-ack");
case LCP_CONF_NAK: return ("conf-nack");
case LCP_CONF_REJ: return ("conf-rej");
case LCP_TERM_REQ: return ("term-req");
case LCP_TERM_ACK: return ("term-ack");
case LCP_CODE_REJ: return ("code-rej");
case LCP_PROTO_REJ: return ("proto-rej");
case LCP_ECHO_REQ: return ("echo-req");
case LCP_ECHO_REPLY: return ("echo-reply");
case LCP_DISC_REQ: return ("discard-req");
}
sprintf (buf, "%xh", type);
return (buf);
}
static char *sppp_ipcp_type_name (u8 type)
{
static char buf [8];
switch (type) {
case IPCP_CONF_REQ: return ("conf-req");
case IPCP_CONF_ACK: return ("conf-ack");
case IPCP_CONF_NAK: return ("conf-nack");
case IPCP_CONF_REJ: return ("conf-rej");
case IPCP_TERM_REQ: return ("term-req");
case IPCP_TERM_ACK: return ("term-ack");
case IPCP_CODE_REJ: return ("code-rej");
}
sprintf (buf, "%xh", type);
return (buf);
}
static void sppp_print_bytes (u_char *p, u16 len)
{
printk (" %x", *p++);
while (--len > 0)
printk ("-%x", *p++);
}
/**
* sppp_rcv - receive and process a WAN PPP frame
* @skb: The buffer to process
* @dev: The device it arrived on
* @p: Unused
* @orig_dev: Unused
*
* Protocol glue. This drives the deferred processing mode the poorer
* cards use. This can be called directly by cards that do not have
* timing constraints but is normally called from the network layer
* after interrupt servicing to process frames queued via netif_rx.
*/
static int sppp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *p, struct net_device *orig_dev)
{
if (dev_net(dev) != &init_net) {
kfree_skb(skb);
return 0;
}
if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
return NET_RX_DROP;
sppp_input(dev,skb);
return 0;
}
static struct packet_type sppp_packet_type = {
.type = __constant_htons(ETH_P_WAN_PPP),
.func = sppp_rcv,
};
static char banner[] __initdata =
KERN_INFO "Cronyx Ltd, Synchronous PPP and CISCO HDLC (c) 1994\n"
KERN_INFO "Linux port (c) 1998 Building Number Three Ltd & "
"Jan \"Yenya\" Kasprzak.\n";
static int __init sync_ppp_init(void)
{
if(debug)
debug=PP_DEBUG;
printk(banner);
skb_queue_head_init(&tx_queue);
dev_add_pack(&sppp_packet_type);
return 0;
}
static void __exit sync_ppp_cleanup(void)
{
dev_remove_pack(&sppp_packet_type);
}
module_init(sync_ppp_init);
module_exit(sync_ppp_cleanup);
module_param(debug, int, 0);
MODULE_LICENSE("GPL");