[4237] in linux-net channel archive
Re: skbuf question
daemon@ATHENA.MIT.EDU (Alan Cox)
Thu Aug 29 20:36:59 1996
From: alan@lxorguk.ukuu.org.uk (Alan Cox)
To: mla@gams.co.at (Michael Lausch)
Date: Wed, 28 Aug 1996 22:23:51 +0100 (BST)
Cc: linux-net@vger.rutgers.edu
In-Reply-To: <199608281552.RAA09509@loki.gams.co.at> from "Michael Lausch" at Aug 28, 96 05:51:59 pm
> I'm porting the SLDcom Synchronous Serial driver for CISCO HDLC
> to linux 2.0.x because they've put the source on their FTP server and
> we purchased such a card.
They've actually seen sense and released the source to the whole driver ?
> The card delivers the frame with the CISCO-HDLC header (4 bytes).
> Now i just ignore the first 4 bytes when copying the data from the
> card to the skb. But i've got the feeling that there must be a better
> way to do this.
According to the info I have the CISCO HDLC header includes some useful
info in those 4 bytes including the protocol type. I started porting some
generic free code for CISCO HDLC stuff to try and make a sonix isdn card
talk to cisco's. This is half ported code but does give you a lot
of useful info on cisco HDLC and what you can pull from the headers
(like IPX protocol info etc) (its also got sync ppp bits but ignore those)
if_sppp.h
/*
* Defines for synchronous PPP/Cisco link level subroutines.
*
* 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 organizations permission to use
* or modify this software as long as this message is kept with the software,
* all derivative works or modified versions.
*
* Version 1.7, Wed Jun 7 22:12:02 MSD 1995
*
*
*
*/
#ifndef _NET_IF_HDLC_H_
#define _NET_IF_HDLC_H_ 1
struct slcp {
u16 state; /* state machine */
u32 magic; /* local magic number */
u_char echoid; /* id of last keepalive echo request */
u_char confid; /* id of last configuration request */
};
struct sipcp {
u16 state; /* state machine */
u_char confid; /* id of last configuration request */
};
struct sppp
{
struct sppp *pp_next; /* next interface in keepalive list */
u32 pp_flags; /* use Cisco protocol instead of PPP */
u16 pp_alivecnt; /* keepalive packets counter */
u16 pp_loopcnt; /* loopback detection counter */
u32 pp_seq; /* local sequence number */
u32 pp_rseq; /* remote sequence number */
struct slcp lcp; /* LCP params */
struct sipcp ipcp; /* IPCP params */
u32 ibytes,obytes; /* Bytes in/out */
u32 ipkts,opkts; /* Packets in/out */
struct timer_list pp_timer;
struct device *pp_if;
};
#define PP_KEEPALIVE 0x01 /* use keepalive protocol */
#define PP_CISCO 0x02 /* use Cisco protocol instead of PPP */
#define PP_TIMO 0x04 /* cp_timeout routine active */
#define PP_DEBUG 0x08
#define PPP_MTU 1500 /* max. transmit unit */
#define LCP_STATE_CLOSED 0 /* LCP state: closed (conf-req sent) */
#define LCP_STATE_ACK_RCVD 1 /* LCP state: conf-ack received */
#define LCP_STATE_ACK_SENT 2 /* LCP state: conf-ack sent */
#define LCP_STATE_OPENED 3 /* LCP state: opened */
#define IPCP_STATE_CLOSED 0 /* IPCP state: closed (conf-req sent) */
#define IPCP_STATE_ACK_RCVD 1 /* IPCP state: conf-ack received */
#define IPCP_STATE_ACK_SENT 2 /* IPCP state: conf-ack sent */
#define IPCP_STATE_OPENED 3 /* IPCP state: opened */
#ifdef __KERNEL__
void sppp_attach (struct device *dev, struct sppp *sp);
void sppp_detach (struct device *dev);
void sppp_input (struct device *dev, struct sk_buff *m);
int sppp_ioctl (struct device *dev, int cmd, void *data);
struct sk_buff *sppp_dequeue (struct device *dev);
int sppp_isempty (struct device *dev);
void sppp_flush (struct device *dev);
#endif
#endif /* _NET_IF_HDLC_H_ */
if_spppsubr.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
*
*/
/*
* 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: if_spppsubr.c,v 1.12 1996/06/10 23:17:45 gpalmer Exp $
*/
#undef DEBUG
#include <linux/modversions.h>
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <linux/route.h>
#include <linux/netdevice.h>
#include "if_sppp.h"
#define MAXALIVECNT 3 /* 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;
u16 protocol;
};
#define PPP_HEADER_LEN sizeof (struct ppp_header)
struct lcp_header {
u8 type;
u8 ident;
u16 len;
};
#define LCP_HEADER_LEN sizeof (struct lcp_header)
struct cisco_packet {
u32 type;
u32 par1;
u32 par2;
u16 rel;
u16 time0;
u16 time1;
};
#define CISCO_PACKET_LEN 18
static struct sppp *spppq;
static struct timer_list sppp_keepalive_timer;
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, long par1, long 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 sppp_output (struct device *dev, struct sk_buff *m,
struct sockaddr *dst, struct rtentry *rt);
/*
* Interface down stub
*/
void if_down(struct device *dev)
{
;
}
/*
* 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;
}
}
/*
* Process the received packet.
*/
void sppp_input (struct device *dev, struct sk_buff *skb)
{
struct ppp_header *h;
struct sppp *sp = (struct sppp *) dev->priv;
int s;
skb->dev=dev;
skb->mac.raw=skb->data;
if (dev->flags & IFF_UP)
{
/* Count received bytes, add FCS and one flag */
sp->ibytes+= skb->len + 3;
sp->ipkts++;
}
if (skb->len <= PPP_HEADER_LEN) {
/* Too small packet, drop it. */
if (sp->pp_flags & PP_DEBUG)
printk ("%s: input packet is too small, %d bytes\n",
dev->name, skb->len);
drop: kfree_skb(skb, FREE_READ);
return;
}
/* Get PPP header. */
h = (struct ppp_header *)skb_pull(skb,sizeof(struct ppp_header));
switch (h->address) {
default: /* Invalid PPP packet. */
invalid: if (sp->pp_flags & PP_DEBUG)
printk ("%s: invalid input packet <0x%x 0x%x 0x%x>\n",
dev->name,
h->address, h->control, ntohs (h->protocol));
goto drop;
case PPP_ALLSTATIONS:
if (h->control != PPP_UI)
goto invalid;
if (sp->pp_flags & PP_CISCO) {
if (sp->pp_flags & PP_DEBUG)
printk ("%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 ("%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 ((struct sppp*) dev, skb);
kfree_skb(skb, FREE_READ);
return;
#ifdef INET
case PPP_IPCP:
if (sp->lcp.state == LCP_STATE_OPENED)
sppp_ipcp_input ((struct sppp*) dev, skb);
kfree_skb(skb, FREE_READ);
return;
case PPP_IP:
if (sp->ipcp.state == IPCP_STATE_OPENED) {
skb->protocol=htons(ETH_P_IP);
netif_rx(skb);
return;
}
break;
#endif
#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);
return;
}
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 ("%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 ((struct sppp*) dev, skb);
kfree_skb(skb, FREE_READ);
return;
#ifdef CONFIG_INET
case ETH_P_IP:
skb->protocol=htons(ETH_P_IP);
netif_rx(skb);
return;
#endif
#ifdef CONFIG_IPX
case ETH_P_IPX:
skb->protocol=htons(ETH_P_IPX);
netif_rx(skb);
return;
#endif
}
break;
}
kfree_skb(skb, FREE_READ);
}
/*
* Handle transmit packets.
*/
static int sppp_hard_header(struct sk_buff *skb, struct device *dev, __u16 type,
void *daddr, void *saddr, unsigned int len)
{
struct sppp *sp=dev->priv;
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_MULTICAST;
h->control = 0;
}
else
{
h->address = PPP_ALLSTATIONS;
h->control = PPP_UI;
}
if(sp->pp_flags & PP_CISCO)
h->protocol = htons(type);
switch(type)
{
case ETH_P_IP:
h->protocol = htons(PPP_IP);
break;
case ETH_P_IPX:
h->protocol = htons(PPP_IPX);
break;
}
}
static int sppp_rebuild_header(void *data, struct device *dev, unsigned long raddr,
struct sk_buff *skb)
{
return 0;
}
/*
* Check if the output queue is empty.
*/
int sppp_isempty (struct device *dev)
{
if(skb_peek(&dev->buffs[0])||skb_peek(&dev->buffs[1])||
skb_peek(&dev->buffs[2]))
return 0;
return 1;
}
/*
* Send keepalive packets, every 10 seconds.
*/
void sppp_keepalive (unsigned long dummy)
{
struct sppp *sp;
unsigned long flags;
save_flags(flags);
cli();
for (sp=spppq; sp; sp=sp->pp_next)
{
struct device *dev = sp->pp_if;
/* Keepalive mode disabled or channel down? */
if (! (sp->pp_flags & PP_KEEPALIVE) ||
! (dev->flags & IFF_RUNNING))
continue;
/* No keepalive in PPP mode if LCP not opened yet. */
if (! (sp->pp_flags & PP_CISCO) &&
sp->lcp.state != LCP_STATE_OPENED)
continue;
if (sp->pp_alivecnt == MAXALIVECNT) {
/* No keepalive packets got. Stop the interface. */
printk ("%s: down\n", dev->name);
if_down (dev);
if (! (sp->pp_flags & PP_CISCO)) {
/* 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);
}
}
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) {
long 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);
}
}
restore_flags(flags);
sppp_keepalive_timer.expires=jiffies+10*HZ;
add_timer(&sppp_keepalive_timer);
}
/*
* Handle incoming PPP Link Control Protocol packets.
*/
void sppp_lcp_input (struct sppp *sp, struct sk_buff *skb)
{
struct lcp_header *h;
struct device *dev = sp->pp_if;
int len = skb->len;
u8 *p, opt[6];
u32 rmagic;
if (len < 4) {
if (sp->pp_flags & PP_DEBUG)
printk ("%s: invalid lcp packet length: %d bytes\n",
dev->name, len);
return;
}
h = (struct lcp_header *)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 ("%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 ("%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 ("%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 ("%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;
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);
/* An ACK has already been sent. */
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 (! (dev->flags & IFF_UP) &&
(dev->flags & IFF_RUNNING)) {
/* Coming out of loopback mode. */
dev->flags |= IFF_UP;
printk ("%s: 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) {
if (sp->pp_flags & PP_DEBUG)
printk ("%s: conf nak: magic glitch\n",
dev->name);
sp->lcp.magic += (jiffies^dev->pa_addr);
} 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, 0);
/* 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 ("%s: invalid lcp echo request packet length: %d bytes\n",
dev->name, len);
break;
}
if (ntohl (*(long*)(h+1)) == sp->lcp.magic) {
/* Line loopback mode detected. */
printk ("%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;
}
*(long*)(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 ("%s: invalid lcp echo reply packet length: %d bytes\n",
dev->name, len);
break;
}
if (ntohl (*(long*)(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 device *dev = sp->pp_if;
if (skb->len != CISCO_PACKET_LEN) {
if (sp->pp_flags & PP_DEBUG)
printk ("%s: invalid cisco packet length: %d bytes\n",
dev->name, skb->len);
return;
}
h = (struct cisco_packet *)skb_pull(skb, sizeof(struct cisco_packet*));
if (sp->pp_flags & PP_DEBUG)
printk ("%s: cisco input: %d bytes <%lxh %lxh %lxh %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 ("%s: unknown cisco packet type: 0x%lx\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. */
if (sp->pp_loopcnt >= MAXALIVECNT) {
printk ("%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 */
sp->pp_seq ^= jiffies + dev->pa_addr;
break;
}
sp->pp_loopcnt = 0;
if (! (dev->flags & IFF_UP) &&
(dev->flags & IFF_RUNNING)) {
dev->flags |= IFF_UP;
printk ("%s: up\n", dev->name);
}
break;
case CISCO_ADDR_REQ:
sppp_cisco_send (sp, CISCO_ADDR_REPLY,
ntohl (dev->pa_addr),
ntohl (dev->pa_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 device *dev = sp->pp_if;
skb=alloc_skb(dev->hard_header_len+PPP_HEADER_LEN+LCP_HEADER_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 ("%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");
}
sp->obytes += skb->len;
/* Control is high priority so it doesnt get queued behind data */
dev_queue_xmit(skb,dev, SOPRI_INTERACTIVE);
}
/*
* Send Cisco keepalive packet.
*/
static void sppp_cisco_send (struct sppp *sp, int type, long par1, long par2)
{
struct ppp_header *h;
struct cisco_packet *ch;
struct sk_buff *skb;
struct 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, sizeof(struct cisco_packet));
ch->type = htonl (type);
ch->par1 = htonl (par1);
ch->par2 = htonl (par2);
ch->rel = -1;
ch->time0 = htons ((u16) (t >> 16));
ch->time1 = htons ((u16) t);
if (sp->pp_flags & PP_DEBUG)
printk ("%s: cisco output: <%lxh %lxh %lxh %xh %xh-%xh>\n",
dev->name, ntohl (ch->type), ch->par1,
ch->par2, ch->rel, ch->time0, ch->time1);
sp->obytes += skb->len;
dev_queue_xmit(skb,dev, SOPRI_INTERACTIVE);
}
/*
* Process an ioctl request. Called on low priority level.
*/
int sppp_close (struct device *dev)
{
struct sppp *sp=dev->priv;
dev->flags &= ~IFF_RUNNING;
sp->lcp.state = LCP_STATE_CLOSED;
sp->ipcp.state = IPCP_STATE_CLOSED;
sppp_clear_timeout (sp);
}
/*
* Flush the interface output queue.
*/
void sppp_flush (struct device *dev)
{
struct sppp *sp = dev->priv;
/* FIXME */
}
int sppp_open (struct device *dev)
{
struct sppp *sp=dev->priv;
sppp_close(dev);
dev->flags |= IFF_RUNNING;
if (!(sp->pp_flags & PP_CISCO))
sppp_lcp_open (sp);
}
int sppp_change_mtu(struct device *dev, int new_mtu)
{
if(new_mtu<128||new_mtu>PPP_MTU)
return -EINVAL;
dev->mtu=new_mtu;
}
void sppp_attach (struct device *dev, struct sppp *sp)
{
int i;
/* 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;
sp->pp_loopcnt = 0;
sp->pp_alivecnt = 0;
sp->pp_seq = 0;
sp->pp_rseq = 0;
sp->lcp.magic = 0;
sp->lcp.state = LCP_STATE_CLOSED;
sp->ipcp.state = IPCP_STATE_CLOSED;
sp->pp_if = dev;
/*
* Device specific setup. All but interrupt handler and
* hard_start_xmit.
*/
dev->priv = sp;
dev->hard_header = sppp_hard_header;
dev->rebuild_header = sppp_rebuild_header;
dev->open = sppp_open;
dev->stop = sppp_close;
dev->tx_queue_len = 10;
dev->type = ARPHRD_PPP;
dev->addr_len = 0;
dev->hard_header_len = sizeof(struct ppp_header);
dev->mtu = PPP_MTU;
/* FIXME
dev->do_ioctl = sppp_do_ioctl;
*/
dev->get_stats = NULL; /* For Now - FIXME */
dev->change_mtu = sppp_change_mtu;
dev->header_cache_bind = NULL;
dev->header_cache_update = NULL;
dev->flags = IFF_MULTICAST;
dev->family = AF_INET;
dev->pa_addr = 0;
dev->pa_brdaddr = 0;
dev->pa_mask = 0;
dev->pa_alen = 4;
for(i=0;i<DEV_NUMBUFFS;i++)
skb_queue_head_init(&dev->buffs[i]);
}
void sppp_detach (struct device *dev)
{
struct sppp **q, *p, *sp = (struct sppp*) dev->priv;
/* 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);
dev->priv=NULL;
}
/*
* 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 device *dev = sp->pp_if;
int len = skb->len;
if (len < 4)
{
if (sp->pp_flags & PP_DEBUG)
printk ("%s: invalid ipcp packet length: %d bytes\n",
dev->name, len);
return;
}
h = (struct lcp_header *)skb_pull(skb,sizeof(struct lcp_header));
if (sp->pp_flags & PP_DEBUG) {
printk ("%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 ("%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, 0);
/* 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, 0);
/* 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, 0);
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;
save_flags(flags);
cli();
sp->pp_flags &= ~PP_TIMO;
if (! (sp->pp_if->flags & IFF_RUNNING) || (sp->pp_flags & PP_CISCO)) {
restore_flags(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;
}
restore_flags(flags);
}
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++);
}
