syncppp.c

linux-2.6.15.6

	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->hard_header = sppp_hard_header;
	dev->rebuild_header = sppp_rebuild_header;
	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->hard_header_cache = NULL;
	dev->header_cache_update = NULL;
	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 ((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");