/* * Generic HDLC support routines for Linux * Frame Relay support * * Copyright (C) 1999 - 2001 Krzysztof Halasa <khc@pm.waw.pl> * * 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. */#include <linux/config.h>#include <linux/module.h>#include <linux/kernel.h>#include <linux/slab.h>#include <linux/poll.h>#include <linux/errno.h>#include <linux/if_arp.h>#include <linux/init.h>#include <linux/skbuff.h>#include <linux/pkt_sched.h>#include <linux/inetdevice.h>#include <linux/lapb.h>#include <linux/rtnetlink.h>#include <linux/hdlc.h>__inline__ pvc_device* find_pvc(hdlc_device *hdlc, u16 dlci){	pvc_device *pvc=hdlc->state.fr.first_pvc;		while (pvc) {		if (netdev_dlci(&pvc->netdev) == dlci)			return pvc;		pvc = pvc->next;	}	return NULL;}__inline__ u16 status_to_dlci(hdlc_device *hdlc, u8 *status,			      int *active, int *new){	*new = (status[2] & 0x08);	*active = (!*new && (status[2] & 0x02));	return ((status[0] & 0x3F)<<4) | ((status[1] & 0x78)>>3);}__inline__ void dlci_to_status(hdlc_device *hdlc, u16 dlci, u8 *status,			       int active, int new){	status[0] = (dlci>>4) & 0x3F;	status[1] = ((dlci<<3) & 0x78) | 0x80;	status[2] = 0x80;	if (new)		status[2] |= 0x08;	else if (active)		status[2] |= 0x02;}static int fr_hard_header(struct sk_buff *skb, struct net_device *dev,			  u16 type, void *daddr, void *saddr, unsigned int len){	u16 head_len;	if (!daddr)		daddr = dev->broadcast;#ifdef CONFIG_HDLC_DEBUG_HARD_HEADER	printk(KERN_DEBUG "%s: fr_hard_header called\n", dev->name);#endif	switch(type) {	case ETH_P_IP:		head_len = 4;		skb_push(skb, head_len);		skb->data[3] = NLPID_IP;		break;	case ETH_P_IPV6:		head_len = 4;		skb_push(skb, head_len);		skb->data[3] = NLPID_IPV6;		break;	case LMI_PROTO:		head_len = 4;		skb_push(skb, head_len);		skb->data[3] = LMI_PROTO;		break;	default:		head_len = 10;		skb_push(skb, head_len);		skb->data[3] = FR_PAD;		skb->data[4] = NLPID_SNAP;		skb->data[5] = FR_PAD;		skb->data[6] = FR_PAD;		skb->data[7] = FR_PAD;		skb->data[8] = type>>8;		skb->data[9] = (u8)type;	}	memcpy(skb->data, daddr, 2);	skb->data[2] = FR_UI;	return head_len;}static int pvc_open(struct net_device *dev){	pvc_device *pvc = dev_to_pvc(dev);	if ((hdlc_to_dev(pvc->master)->flags & IFF_UP) == 0)		return -EIO;  /* Master must be UP in order to activate PVC */	if (pvc->master->state.fr.settings.lmi != LMI_NONE)		pvc->state.active = 0;	else		pvc->state.active = 1;	pvc->state.new = 0;	pvc->master->state.fr.changed = 1;	return 0;}static int pvc_close(struct net_device *dev){	pvc_device *pvc = dev_to_pvc(dev);	pvc->state.active = pvc->state.new = 0;	pvc->master->state.fr.changed = 1;	return 0;}static int pvc_xmit(struct sk_buff *skb, struct net_device *dev){	pvc_device *pvc = dev_to_pvc(dev);	if (pvc->state.active) {		skb->dev = hdlc_to_dev(pvc->master);		pvc->stats.tx_bytes += skb->len;		pvc->stats.tx_packets++;		if (pvc->state.fecn)			pvc->stats.tx_compressed++; /* TX Congestion counter */		dev_queue_xmit(skb);	} else {		pvc->stats.tx_dropped++;		dev_kfree_skb(skb);	}	return 0;}static struct net_device_stats *pvc_get_stats(struct net_device *dev){	pvc_device *pvc = dev_to_pvc(dev);	return &pvc->stats;}static int pvc_change_mtu(struct net_device *dev, int new_mtu){	if ((new_mtu < 68) || (new_mtu > HDLC_MAX_MTU))		return -EINVAL;	dev->mtu = new_mtu;	return 0;}static inline void fr_log_dlci_active(pvc_device *pvc){	printk(KERN_INFO "%s: %sactive%s\n", pvc_to_name(pvc),	       pvc->state.active ? "" : "in",	       pvc->state.new ? " new" : "");}static inline u8 fr_lmi_nextseq(u8 x){	x++;	return x ? x : 1;}static void fr_lmi_send(hdlc_device *hdlc, int fullrep){	struct sk_buff *skb;	pvc_device *pvc = hdlc->state.fr.first_pvc;	int len = (hdlc->state.fr.settings.lmi == LMI_ANSI) ? LMI_ANSI_LENGTH		: LMI_LENGTH;	int stat_len = 3;	u8 *data;	int i = 0;	if (hdlc->state.fr.settings.dce && fullrep) {		len += hdlc->state.fr.pvc_count * (2 + stat_len);		if (len > HDLC_MAX_MTU) {			printk(KERN_WARNING "%s: Too many PVCs while sending "			       "LMI full report\n", hdlc_to_name(hdlc));			return;		}	}	skb = dev_alloc_skb(len);	if (!skb) {		printk(KERN_WARNING "%s: Memory squeeze on fr_lmi_send()\n",			       hdlc_to_name(hdlc));		return;	}	memset(skb->data, 0, len);	skb_reserve(skb, 4);	fr_hard_header(skb, hdlc_to_dev(hdlc), LMI_PROTO, NULL, NULL, 0);	data = skb->tail;	data[i++] = LMI_CALLREF;	data[i++] = hdlc->state.fr.settings.dce		? LMI_STATUS : LMI_STATUS_ENQUIRY;	if (hdlc->state.fr.settings.lmi == LMI_ANSI)		data[i++] = LMI_ANSI_LOCKSHIFT;	data[i++] = (hdlc->state.fr.settings.lmi == LMI_CCITT)		? LMI_CCITT_REPTYPE : LMI_REPTYPE;	data[i++] = LMI_REPT_LEN;	data[i++] = fullrep ? LMI_FULLREP : LMI_INTEGRITY;	data[i++] = (hdlc->state.fr.settings.lmi == LMI_CCITT)		? LMI_CCITT_ALIVE : LMI_ALIVE;	data[i++] = LMI_INTEG_LEN;	data[i++] = hdlc->state.fr.txseq =fr_lmi_nextseq(hdlc->state.fr.txseq);	data[i++] = hdlc->state.fr.rxseq;	if (hdlc->state.fr.settings.dce && fullrep) {		while (pvc) {			data[i++] = (hdlc->state.fr.settings.lmi == LMI_CCITT)				? LMI_CCITT_PVCSTAT : LMI_PVCSTAT;			data[i++] = stat_len;			if (hdlc->state.fr.reliable &&			    (pvc->netdev.flags & IFF_UP) &&			    !pvc->state.active &&			    !pvc->state.new) {				pvc->state.new = 1;				fr_log_dlci_active(pvc);			}			dlci_to_status(hdlc, netdev_dlci(&pvc->netdev),				       data + i,				       pvc->state.active, pvc->state.new);			i += stat_len;			pvc = pvc->next;		}	}	skb_put(skb, i);	skb->priority = TC_PRIO_CONTROL;	skb->dev = hdlc_to_dev(hdlc);	dev_queue_xmit(skb);}static void fr_timer(unsigned long arg){	hdlc_device *hdlc = (hdlc_device*)arg;	int i, cnt = 0, reliable;	u32 list;	if (hdlc->state.fr.settings.dce)		reliable = (jiffies - hdlc->state.fr.last_poll <			    hdlc->state.fr.settings.t392 * HZ);	else {		hdlc->state.fr.last_errors <<= 1; /* Shift the list */		if (hdlc->state.fr.request) {			if (hdlc->state.fr.reliable)				printk(KERN_INFO "%s: No LMI status reply "				       "received\n", hdlc_to_name(hdlc));			hdlc->state.fr.last_errors |= 1;		}		list = hdlc->state.fr.last_errors;		for (i = 0; i < hdlc->state.fr.settings.n393; i++, list >>= 1)			cnt += (list & 1);	/* errors count */		reliable = (cnt < hdlc->state.fr.settings.n392);	}	if (hdlc->state.fr.reliable != reliable) {		pvc_device *pvc = hdlc->state.fr.first_pvc;		hdlc->state.fr.reliable = reliable;		printk(KERN_INFO "%s: Link %sreliable\n", hdlc_to_name(hdlc),		       reliable ? "" : "un");		if (reliable) {			hdlc->state.fr.n391cnt = 0; /* Request full status */			hdlc->state.fr.changed = 1;		} else {			while (pvc) {	/* Deactivate all PVCs */				pvc->state.new = pvc->state.active = 0;				pvc = pvc->next;			}		}	}	if (hdlc->state.fr.settings.dce)		hdlc->state.fr.timer.expires = jiffies +			hdlc->state.fr.settings.t392 * HZ;	else {		if (hdlc->state.fr.n391cnt)			hdlc->state.fr.n391cnt--;		fr_lmi_send(hdlc, hdlc->state.fr.n391cnt == 0);		hdlc->state.fr.request = 1;		hdlc->state.fr.timer.expires = jiffies +			hdlc->state.fr.settings.t391 * HZ;	}	hdlc->state.fr.timer.function = fr_timer;	hdlc->state.fr.timer.data = arg;	add_timer(&hdlc->state.fr.timer);}static int fr_lmi_recv(hdlc_device *hdlc, struct sk_buff *skb){	int stat_len;	pvc_device *pvc;	int reptype = -1, error;	u8 rxseq, txseq;	int i;	if (skb->len < ((hdlc->state.fr.settings.lmi == LMI_ANSI)			? LMI_ANSI_LENGTH : LMI_LENGTH)) {		printk(KERN_INFO "%s: Short LMI frame\n", hdlc_to_name(hdlc));		return 1;	}	if (skb->data[5] != (!hdlc->state.fr.settings.dce ?			     LMI_STATUS : LMI_STATUS_ENQUIRY)) {		printk(KERN_INFO "%s: LMI msgtype=%x, Not LMI status %s\n",		       hdlc_to_name(hdlc), skb->data[2],		       hdlc->state.fr.settings.dce ? "enquiry" : "reply");		return 1;	}	i = (hdlc->state.fr.settings.lmi == LMI_ANSI) ? 7 : 6;	if (skb->data[i] !=	    ((hdlc->state.fr.settings.lmi == LMI_CCITT)	     ? LMI_CCITT_REPTYPE : LMI_REPTYPE)) {		printk(KERN_INFO "%s: Not a report type=%x\n",		       hdlc_to_name(hdlc), skb->data[i]);		return 1;	}	i++;	i++;				/* Skip length field */	reptype = skb->data[i++];	if (skb->data[i]!=	    ((hdlc->state.fr.settings.lmi == LMI_CCITT)	     ? LMI_CCITT_ALIVE : LMI_ALIVE)) {		printk(KERN_INFO "%s: Unsupported status element=%x\n",		       hdlc_to_name(hdlc), skb->data[i]);		return 1;	}	i++;	i++;			/* Skip length field */	hdlc->state.fr.rxseq = skb->data[i++]; /* TX sequence from peer */	rxseq = skb->data[i++];	/* Should confirm our sequence */	txseq = hdlc->state.fr.txseq;	if (hdlc->state.fr.settings.dce) {		if (reptype != LMI_FULLREP && reptype != LMI_INTEGRITY) {			printk(KERN_INFO "%s: Unsupported report type=%x\n",			       hdlc_to_name(hdlc), reptype);			return 1;		}	}	error = 0;	if (!hdlc->state.fr.reliable)		error = 1;	if (rxseq == 0 || rxseq != txseq) {		hdlc->state.fr.n391cnt = 0; /* Ask for full report next time */		error = 1;	}	if (hdlc->state.fr.settings.dce) {		if (hdlc->state.fr.fullrep_sent && !error) {/* Stop sending full report - the last one has been confirmed by DTE */			hdlc->state.fr.fullrep_sent = 0;			pvc = hdlc->state.fr.first_pvc;			while (pvc) {				if (pvc->state.new) {					pvc->state.new = 0;					pvc->state.active = 1;					fr_log_dlci_active(pvc);/* Tell DTE that new PVC is now active */					hdlc->state.fr.changed = 1;				}				pvc = pvc->next;			}		}