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/*
 * Generic HDLC support routines for Linux
 * Frame Relay support
 *
 * Copyright (C) 1999 - 2003 Krzysztof Halasa <khc@pm.waw.pl>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License
 * as published by the Free Software Foundation.
 *
 
 Theory of PVC state in DCE mode:
 
 (exist,new) -> 0,0 when "PVC create" or if "link unreliable"
         0,x -> 1,1 if "link reliable" when sending FULL STATUS
         1,1 -> 1,0 if received FULL STATUS ACK
 
 (active)    -> 0 when "ifconfig PVC down" or "link unreliable" or "PVC create"
             -> 1 when "PVC up" and (exist,new) = 1,0
*/
 
#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/random.h>
#include <linux/inetdevice.h>
#include <linux/lapb.h>
#include <linux/rtnetlink.h>
#include <linux/etherdevice.h>
#include <linux/hdlc.h>
 
#undef DEBUG_PKT
#undef DEBUG_ECN
 
#define MAXLEN_LMISTAT  20	/* max size of status enquiry frame */
 
#define PVC_STATE_NEW	 0x01
#define PVC_STATE_ACTIVE 0x02
#define PVC_STATE_FECN	 0x08 /* FECN condition */
#define PVC_STATE_BECN	 0x10 /* BECN condition */
 
 
#define FR_UI		 0x03
#define FR_PAD		 0x00
 
#define NLPID_IP	 0xCC
#define NLPID_IPV6	 0x8E
#define NLPID_SNAP	 0x80
#define NLPID_PAD	 0x00
#define NLPID_Q933	 0x08
 
 
#define LMI_DLCI                   0 /* LMI DLCI */
#define LMI_PROTO               0x08
#define LMI_CALLREF             0x00 /* Call Reference */
#define LMI_ANSI_LOCKSHIFT      0x95 /* ANSI lockshift */
#define LMI_REPTYPE                1 /* report type */
#define LMI_CCITT_REPTYPE       0x51
#define LMI_ALIVE                  3 /* keep alive */
#define LMI_CCITT_ALIVE         0x53
#define LMI_PVCSTAT                7 /* pvc status */
#define LMI_CCITT_PVCSTAT       0x57
#define LMI_FULLREP                0 /* full report  */
#define LMI_INTEGRITY              1 /* link integrity report */
#define LMI_SINGLE                 2 /* single pvc report */
#define LMI_STATUS_ENQUIRY      0x75
#define LMI_STATUS              0x7D /* reply */
 
#define LMI_REPT_LEN               1 /* report type element length */
#define LMI_INTEG_LEN              2 /* link integrity element length */
 
#define LMI_LENGTH                13 /* standard LMI frame length */
#define LMI_ANSI_LENGTH           14
 
 
typedef struct {
#if defined(__LITTLE_ENDIAN_BITFIELD)
	unsigned ea1:	1;
	unsigned cr:	1;
	unsigned dlcih:	6;
 
	unsigned ea2:	1;
	unsigned de:	1;
	unsigned becn:	1;
	unsigned fecn:	1;
	unsigned dlcil:	4;
#else
	unsigned dlcih:	6;
	unsigned cr:	1;
	unsigned ea1:	1;
 
	unsigned dlcil:	4;
	unsigned fecn:	1;
	unsigned becn:	1;
	unsigned de:	1;
	unsigned ea2:	1;
#endif
}__attribute__ ((packed)) fr_hdr;
 
 
static inline u16 q922_to_dlci(u8 *hdr)
{
	return ((hdr[0] & 0xFC) << 2) | ((hdr[1] & 0xF0) >> 4);
}
 
 
 
static inline void dlci_to_q922(u8 *hdr, u16 dlci)
{
	hdr[0] = (dlci >> 2) & 0xFC;
	hdr[1] = ((dlci << 4) & 0xF0) | 0x01;
}
 
 
 
static inline pvc_device* find_pvc(hdlc_device *hdlc, u16 dlci)
{
	pvc_device *pvc = hdlc->state.fr.first_pvc;
 
	while (pvc) {
		if (pvc->dlci == dlci)
			return pvc;
		if (pvc->dlci > dlci)
			return NULL; /* the listed is sorted */
		pvc = pvc->next;
	}
 
	return NULL;
}
 
 
static inline pvc_device* add_pvc(hdlc_device *hdlc, u16 dlci)
{
	pvc_device *pvc, **pvc_p = &hdlc->state.fr.first_pvc;
 
	while (*pvc_p) {
		if ((*pvc_p)->dlci == dlci)
			return *pvc_p;
		if ((*pvc_p)->dlci > dlci)
			break;	/* the list is sorted */
		pvc_p = &(*pvc_p)->next;
	}
 
	pvc = kmalloc(sizeof(pvc_device), GFP_ATOMIC);
	if (!pvc)
		return NULL;
 
	memset(pvc, 0, sizeof(pvc_device));
	pvc->dlci = dlci;
	pvc->master = hdlc;
	pvc->next = *pvc_p;	/* Put it in the chain */
	*pvc_p = pvc;
	return pvc;
}
 
 
static inline int pvc_is_used(pvc_device *pvc)
{
	return pvc->main != NULL || pvc->ether != NULL;
}
 
 
static inline void delete_unused_pvcs(hdlc_device *hdlc)
{
	pvc_device **pvc_p = &hdlc->state.fr.first_pvc;
 
	while (*pvc_p) {
		if (!pvc_is_used(*pvc_p)) {
			pvc_device *pvc = *pvc_p;
			*pvc_p = pvc->next;
			kfree(pvc);
			continue;
		}
		pvc_p = &(*pvc_p)->next;
	}
}
 
 
static inline struct net_device** get_dev_p(pvc_device *pvc, int type)
{
	if (type == ARPHRD_ETHER)
		return &pvc->ether;
	else
		return &pvc->main;
}
 
 
static inline u16 status_to_dlci(u8 *status, int *active, int *new)
{
	*new = (status[2] & 0x08) ? 1 : 0;
	*active = (status[2] & 0x02) ? 1 : 0;
 
	return ((status[0] & 0x3F) << 4) | ((status[1] & 0x78) >> 3);
}
 
 
static inline void dlci_to_status(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_p, u16 dlci)
{
	u16 head_len;
	struct sk_buff *skb = *skb_p;
 
	switch (skb->protocol) {
	case __constant_ntohs(ETH_P_IP):
		head_len = 4;
		skb_push(skb, head_len);
		skb->data[3] = NLPID_IP;
		break;
 
	case __constant_ntohs(ETH_P_IPV6):
		head_len = 4;
		skb_push(skb, head_len);
		skb->data[3] = NLPID_IPV6;
		break;
 
	case __constant_ntohs(LMI_PROTO):
		head_len = 4;
		skb_push(skb, head_len);
		skb->data[3] = LMI_PROTO;
		break;
 
	case __constant_ntohs(ETH_P_802_3):
		head_len = 10;
		if (skb_headroom(skb) < head_len) {
			struct sk_buff *skb2 = skb_realloc_headroom(skb,
								    head_len);
			if (!skb2)
				return -ENOBUFS;
			dev_kfree_skb(skb);
			skb = *skb_p = skb2;
		}
		skb_push(skb, head_len);
		skb->data[3] = FR_PAD;
		skb->data[4] = NLPID_SNAP;
		skb->data[5] = FR_PAD;
		skb->data[6] = 0x80;
		skb->data[7] = 0xC2;
		skb->data[8] = 0x00;
		skb->data[9] = 0x07; /* bridged Ethernet frame w/out FCS */
		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;
		*(u16*)(skb->data + 8) = skb->protocol;
	}
 
	dlci_to_q922(skb->data, dlci);
	skb->data[2] = FR_UI;
	return 0;
}
 
 
 
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->open_count++ == 0) {
		if (pvc->master->state.fr.settings.lmi == LMI_NONE)
			pvc->state.active = 1;
 
		pvc->master->state.fr.dce_changed = 1;
	}
	return 0;
}
 
 
 
static int pvc_close(struct net_device *dev)
{
	pvc_device *pvc = dev_to_pvc(dev);
 
	if (--pvc->open_count == 0) {
		if (pvc->master->state.fr.settings.lmi == LMI_NONE)
			pvc->state.active = 0;
 
		if (pvc->master->state.fr.settings.dce) {
			pvc->master->state.fr.dce_changed = 1;
			pvc->state.active = 0;
		}
	}
	return 0;
}
 
 
 
int pvc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
	pvc_device *pvc = dev_to_pvc(dev);
	fr_proto_pvc_info info;
 
	if (ifr->ifr_settings.type == IF_GET_PROTO) {
		if (dev->type == ARPHRD_ETHER)
			ifr->ifr_settings.type = IF_PROTO_FR_ETH_PVC;
		else
			ifr->ifr_settings.type = IF_PROTO_FR_PVC;
 
		if (ifr->ifr_settings.size < sizeof(info)) {
			/* data size wanted */
			ifr->ifr_settings.size = sizeof(info);
			return -ENOBUFS;
		}
 
		info.dlci = pvc->dlci;
		memcpy(info.master, hdlc_to_name(pvc->master), IFNAMSIZ);
		if (copy_to_user(ifr->ifr_settings.ifs_ifsu.fr_pvc_info,
				 &info, sizeof(info)))
			return -EFAULT;
		return 0;
	}
 
	return -EINVAL;
}
 
 
static inline struct net_device_stats *pvc_get_stats(struct net_device *dev)
{
	return (struct net_device_stats *)
		((char *)dev + sizeof(struct net_device));
}
 
 
 
static int pvc_xmit(struct sk_buff *skb, struct net_device *dev)
{
	pvc_device *pvc = dev_to_pvc(dev);
	struct net_device_stats *stats = pvc_get_stats(dev);
 
	if (pvc->state.active) {
		if (dev->type == ARPHRD_ETHER) {
			int pad = ETH_ZLEN - skb->len;
			if (pad > 0) { /* Pad the frame with zeros */
				int len = skb->len;
				if (skb_tailroom(skb) < pad)
					if (pskb_expand_head(skb, 0, pad,
							     GFP_ATOMIC)) {
						stats->tx_dropped++;
						dev_kfree_skb(skb);
						return 0;
					}
				skb_put(skb, pad);
				memset(skb->data + len, 0, pad);
			}
			skb->protocol = __constant_htons(ETH_P_802_3);
		}
		if (!fr_hard_header(&skb, pvc->dlci)) {
			stats->tx_bytes += skb->len;
			stats->tx_packets++;
			if (pvc->state.fecn) /* TX Congestion counter */
				stats->tx_compressed++;
			skb->dev = hdlc_to_dev(pvc->master);
			dev_queue_xmit(skb);
			return 0;
		}
	}
 
	stats->tx_dropped++;
	dev_kfree_skb(skb);
	return 0;
}
 
 
 
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: DLCI %d [%s%s%s]%s %s\n",
	       hdlc_to_name(pvc->master),
	       pvc->dlci,
	       pvc->main ? pvc->main->name : "",
	       pvc->main && pvc->ether ? " " : "",
	       pvc->ether ? pvc->ether->name : "",
	       pvc->state.new ? " new" : "",
	       !pvc->state.exist ? "deleted" :
	       pvc->state.active ? "active" : "inactive");
}
 
 
 
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.dce_pvc_count * (2 + stat_len);
		if (len > HDLC_MAX_MRU) {
			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);
	skb->protocol = __constant_htons(LMI_PROTO);
	fr_hard_header(&skb, LMI_DLCI);
	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;
 
			/* LMI start/restart */
			if (hdlc->state.fr.reliable && !pvc->state.exist) {
				pvc->state.exist = pvc->state.new = 1;
				fr_log_dlci_active(pvc);
			}
 
			/* ifconfig PVC up */
			if (pvc->open_count && !pvc->state.active &&
			    pvc->state.exist && !pvc->state.new) {
				pvc->state.active = 1;
				fr_log_dlci_active(pvc);
			}
 
			dlci_to_status(pvc->dlci, 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);
	skb->nh.raw = skb->data;
 
	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.dce_changed = 1;
		} else {
			while (pvc) {	/* Deactivate all PVCs */
				pvc->state.exist = 0;
				pvc->state.active = pvc->state.new = 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, no_ram;
	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;
 
/* Tell DTE that new PVC is now active */
					hdlc->state.fr.dce_changed = 1;
				}
				pvc = pvc->next;
			}
		}
 
		if (hdlc->state.fr.dce_changed) {
			reptype = LMI_FULLREP;
			hdlc->state.fr.fullrep_sent = 1;
			hdlc->state.fr.dce_changed = 0;
		}
 
		fr_lmi_send(hdlc, reptype == LMI_FULLREP ? 1 : 0);
		return 0;
	}
 
	/* DTE */
 
	if (reptype != LMI_FULLREP || error)
		return 0;
 
	stat_len = 3;
	pvc = hdlc->state.fr.first_pvc;
 
	while (pvc) {
		pvc->state.deleted = 1;
		pvc = pvc->next;
	}
 
	no_ram = 0;
	while (skb->len >= i + 2 + stat_len) {
		u16 dlci;
		unsigned int active, new;
 
		if (skb->data[i] != ((hdlc->state.fr.settings.lmi == LMI_CCITT)
				     ? LMI_CCITT_PVCSTAT : LMI_PVCSTAT)) {
			printk(KERN_WARNING "%s: Invalid PVCSTAT ID: %x\n",
			       hdlc_to_name(hdlc), skb->data[i]);
			return 1;
		}
		i++;
 
		if (skb->data[i] != stat_len) {
			printk(KERN_WARNING "%s: Invalid PVCSTAT length: %x\n",
			       hdlc_to_name(hdlc), skb->data[i]);
			return 1;
		}
		i++;
 
		dlci = status_to_dlci(skb->data + i, &active, &new);
 
		pvc = add_pvc(hdlc, dlci);
 
		if (!pvc && !no_ram) {
			printk(KERN_WARNING
			       "%s: Memory squeeze on fr_lmi_recv()\n",
			       hdlc_to_name(hdlc));
			no_ram = 1;
		}
 
		if (pvc) {
			pvc->state.exist = 1;
			pvc->state.deleted = 0;
			if (active != pvc->state.active ||
			    new != pvc->state.new) {
				pvc->state.new = new;
				pvc->state.active = active;
				fr_log_dlci_active(pvc);
			}
		}
 
		i += stat_len;
	}
 
	pvc = hdlc->state.fr.first_pvc;
 
	while (pvc) {
		if (pvc->state.deleted && pvc->state.exist) {
			pvc->state.active = pvc->state.new = 0;
			pvc->state.exist = 0;
			fr_log_dlci_active(pvc);
		}
		pvc = pvc->next;
	}
 
	/* Next full report after N391 polls */
	hdlc->state.fr.n391cnt = hdlc->state.fr.settings.n391;
 
	return 0;
}
 
 
 
static void fr_rx(struct sk_buff *skb)
{
	hdlc_device *hdlc = dev_to_hdlc(skb->dev);
	fr_hdr *fh = (fr_hdr*)skb->data;
	u8 *data = skb->data;
	u16 dlci;
	pvc_device *pvc;
	struct net_device *dev = NULL;
 
	if (skb->len <= 4 || fh->ea1 || data[2] != FR_UI)
		goto rx_error;
 
	dlci = q922_to_dlci(skb->data);
 
	if (dlci == LMI_DLCI) {
		if (hdlc->state.fr.settings.lmi == LMI_NONE)
			goto rx_error; /* LMI packet with no LMI? */
 
		if (data[3] == LMI_PROTO) {
			if (fr_lmi_recv(hdlc, skb))
				goto rx_error;
			else {
				/* No request pending */
				hdlc->state.fr.request = 0;
				hdlc->state.fr.last_poll = jiffies;
				dev_kfree_skb_any(skb);
				return;
			}
		}
 
		printk(KERN_INFO "%s: Received non-LMI frame with LMI DLCI\n",
		       hdlc_to_name(hdlc));
		goto rx_error;
	}
 
	pvc = find_pvc(hdlc, dlci);
	if (!pvc) {
#ifdef DEBUG_PKT
		printk(KERN_INFO "%s: No PVC for received frame's DLCI %d\n",
		       hdlc_to_name(hdlc), dlci);
#endif
		dev_kfree_skb_any(skb);
		return;
	}
 
	if (pvc->state.fecn != fh->fecn) {
#ifdef DEBUG_ECN
		printk(KERN_DEBUG "%s: DLCI %d FECN O%s\n", hdlc_to_name(pvc),
		       dlci, fh->fecn ? "N" : "FF");
#endif
		pvc->state.fecn ^= 1;
	}
 
	if (pvc->state.becn != fh->becn) {
#ifdef DEBUG_ECN
		printk(KERN_DEBUG "%s: DLCI %d BECN O%s\n", hdlc_to_name(pvc),
		       dlci, fh->becn ? "N" : "FF");
#endif
		pvc->state.becn ^= 1;
	}
 
 
	if (data[3] == NLPID_IP) {
		skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
		dev = pvc->main;
		skb->protocol = htons(ETH_P_IP);
 
	} else if (data[3] == NLPID_IPV6) {
		skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
		dev = pvc->main;
		skb->protocol = htons(ETH_P_IPV6);
 
	} else if (skb->len > 10 && data[3] == FR_PAD &&
		   data[4] == NLPID_SNAP && data[5] == FR_PAD) {
		u16 oui = ntohs(*(u16*)(data + 6));
		u16 pid = ntohs(*(u16*)(data + 8));
		skb_pull(skb, 10);
 
		switch ((((u32)oui) << 16) | pid) {
		case ETH_P_ARP: /* routed frame with SNAP */
		case ETH_P_IPX:
		case ETH_P_IP:	/* a long variant */
		case ETH_P_IPV6:
			dev = pvc->main;
			skb->protocol = htons(pid);
			break;
 
		case 0x80C20007: /* bridged Ethernet frame */
			if ((dev = pvc->ether) != NULL)
				skb->protocol = eth_type_trans(skb, dev);
			break;
 
		default:
			printk(KERN_INFO "%s: Unsupported protocol, OUI=%x "
			       "PID=%x\n", hdlc_to_name(hdlc), oui, pid);
			dev_kfree_skb_any(skb);
			return;
		}
	} else {
		printk(KERN_INFO "%s: Unsupported protocol, NLPID=%x "
		       "length = %i\n", hdlc_to_name(hdlc), data[3], skb->len);
		dev_kfree_skb_any(skb);
		return;
	}
 
	if (dev) {
		struct net_device_stats *stats = pvc_get_stats(dev);
		stats->rx_packets++; /* PVC traffic */
		stats->rx_bytes += skb->len;
		if (pvc->state.becn)
			stats->rx_compressed++;
		skb->dev = dev;
		netif_rx(skb);
	} else
		dev_kfree_skb_any(skb);
 
	return;
 
 rx_error:
	hdlc->stats.rx_errors++; /* Mark error */
	dev_kfree_skb_any(skb);
}
 
 
 
static int fr_open(hdlc_device *hdlc)
{
	if (hdlc->state.fr.settings.lmi != LMI_NONE) {
		hdlc->state.fr.last_poll = 0;
		hdlc->state.fr.reliable = 0;
		hdlc->state.fr.dce_changed = 1;
		hdlc->state.fr.request = 0;
		hdlc->state.fr.fullrep_sent = 0;
		hdlc->state.fr.last_errors = 0xFFFFFFFF;
		hdlc->state.fr.n391cnt = 0;
		hdlc->state.fr.txseq = hdlc->state.fr.rxseq = 0;
 
		init_timer(&hdlc->state.fr.timer);
		/* First poll after 1 s */
		hdlc->state.fr.timer.expires = jiffies + HZ;
		hdlc->state.fr.timer.function = fr_timer;
		hdlc->state.fr.timer.data = (unsigned long)hdlc;
		add_timer(&hdlc->state.fr.timer);
	} else
		hdlc->state.fr.reliable = 1;
 
	return 0;
}
 
 
 
static void fr_close(hdlc_device *hdlc)
{
	pvc_device *pvc = hdlc->state.fr.first_pvc;
 
	if (hdlc->state.fr.settings.lmi != LMI_NONE)
		del_timer_sync(&hdlc->state.fr.timer);
 
	while (pvc) {		/* Shutdown all PVCs for this FRAD */
		if (pvc->main)
			dev_close(pvc->main);
		if (pvc->ether)
			dev_close(pvc->ether);
		pvc->state.active = pvc->state.new = pvc->state.fecn =
			pvc->state.becn = 0;
		pvc->state.exist = 0;
		pvc = pvc->next;
	}
}
 
 
static int fr_add_pvc(hdlc_device *hdlc, unsigned int dlci, int type)
{
	pvc_device *pvc = NULL;
	struct net_device *dev;
	int result, used;
	char * prefix = "pvc%d";
 
	if (type == ARPHRD_ETHER)
		prefix = "pvceth%d";
 
	if ((pvc = add_pvc(hdlc, dlci)) == NULL) {
		printk(KERN_WARNING "%s: Memory squeeze on fr_add_pvc()\n",
		       hdlc_to_name(hdlc));
		return -ENOBUFS;
	}
 
	if (*get_dev_p(pvc, type))
		return -EEXIST;
 
	used = pvc_is_used(pvc);
 
	dev = kmalloc(sizeof(struct net_device) +
		      sizeof(struct net_device_stats), GFP_KERNEL);
	if (!dev) {
		printk(KERN_WARNING "%s: Memory squeeze on fr_pvc()\n",
		       hdlc_to_name(hdlc));
		delete_unused_pvcs(hdlc);
		return -ENOBUFS;
	}
	memset(dev, 0, sizeof(struct net_device) +
	       sizeof(struct net_device_stats));
 
	if (type == ARPHRD_ETHER) {
		ether_setup(dev);
		memcpy(dev->dev_addr, "\x00\x01", 2);
                get_random_bytes(dev->dev_addr + 2, ETH_ALEN - 2);
	} else {
		dev->type = ARPHRD_DLCI;
		dev->flags = IFF_POINTOPOINT;
		dev->hard_header_len = 10;
		dev->addr_len = 2;
		*(u16*)dev->dev_addr = htons(dlci);
		dlci_to_q922(dev->broadcast, dlci);
	}
	dev->hard_start_xmit = pvc_xmit;
	dev->get_stats = pvc_get_stats;
	dev->open = pvc_open;
	dev->stop = pvc_close;
	dev->do_ioctl = pvc_ioctl;
	dev->change_mtu = pvc_change_mtu;
	dev->mtu = HDLC_MAX_MTU;
	dev->tx_queue_len = 0;
	dev->priv = pvc;
 
	result = dev_alloc_name(dev, prefix);
	if (result < 0) {
		kfree(dev);
		delete_unused_pvcs(hdlc);
		return result;
	}
 
	if (register_netdevice(dev) != 0) {
		kfree(dev);
		delete_unused_pvcs(hdlc);
		return -EIO;
	}
 
	*get_dev_p(pvc, type) = dev;
	if (!used) {
		hdlc->state.fr.dce_changed = 1;
		hdlc->state.fr.dce_pvc_count++;
	}
	return 0;
}
 
 
 
static int fr_del_pvc(hdlc_device *hdlc, unsigned int dlci, int type)
{
	pvc_device *pvc;
	struct net_device *dev;
 
	if ((pvc = find_pvc(hdlc, dlci)) == NULL)
		return -ENOENT;
 
	if ((dev = *get_dev_p(pvc, type)) == NULL)
		return -ENOENT;
 
	if (dev->flags & IFF_UP)
		return -EBUSY;		/* PVC in use */
 
	unregister_netdevice(dev);
	kfree(dev);
	*get_dev_p(pvc, type) = NULL;
 
	if (!pvc_is_used(pvc)) {
		hdlc->state.fr.dce_pvc_count--;
		hdlc->state.fr.dce_changed = 1;
	}
	delete_unused_pvcs(hdlc);
	return 0;
}
 
 
 
static void fr_destroy(hdlc_device *hdlc)
{
	pvc_device *pvc = hdlc->state.fr.first_pvc;
	while (pvc) {
		pvc_device *next = pvc->next;
		if (pvc->main) {
			unregister_netdevice(pvc->main);
			kfree(pvc->main);
		}
		if (pvc->ether) {
			unregister_netdevice(pvc->ether);
			kfree(pvc->ether);
		}
		kfree(pvc);
		pvc = next;
	}
 
	hdlc->state.fr.first_pvc = NULL; /* All PVCs destroyed */
	hdlc->state.fr.dce_pvc_count = 0;
	hdlc->state.fr.dce_changed = 1;
}
 
 
 
int hdlc_fr_ioctl(hdlc_device *hdlc, struct ifreq *ifr)
{
	fr_proto *fr_s = ifr->ifr_settings.ifs_ifsu.fr;
	const size_t size = sizeof(fr_proto);
	fr_proto new_settings;
	struct net_device *dev = hdlc_to_dev(hdlc);
	fr_proto_pvc pvc;
	int result;
 
	switch (ifr->ifr_settings.type) {
	case IF_GET_PROTO:
		ifr->ifr_settings.type = IF_PROTO_FR;
		if (ifr->ifr_settings.size < size) {
			ifr->ifr_settings.size = size; /* data size wanted */
			return -ENOBUFS;
		}
		if (copy_to_user(fr_s, &hdlc->state.fr.settings, size))
			return -EFAULT;
		return 0;
 
	case IF_PROTO_FR:
		if(!capable(CAP_NET_ADMIN))
			return -EPERM;
 
		if(dev->flags & IFF_UP)
			return -EBUSY;
 
		if (copy_from_user(&new_settings, fr_s, size))
			return -EFAULT;
 
		if (new_settings.lmi == LMI_DEFAULT)
			new_settings.lmi = LMI_ANSI;
 
		if ((new_settings.lmi != LMI_NONE &&
		     new_settings.lmi != LMI_ANSI &&
		     new_settings.lmi != LMI_CCITT) ||
		    new_settings.t391 < 1 ||
		    new_settings.t392 < 2 ||
		    new_settings.n391 < 1 ||
		    new_settings.n392 < 1 ||
		    new_settings.n393 < new_settings.n392 ||
		    new_settings.n393 > 32 ||
		    (new_settings.dce != 0 &&
		     new_settings.dce != 1))
			return -EINVAL;
 
		result=hdlc->attach(hdlc, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
		if (result)
			return result;
 
		if (hdlc->proto != IF_PROTO_FR) {
			hdlc_proto_detach(hdlc);
			hdlc->state.fr.first_pvc = NULL;
			hdlc->state.fr.dce_pvc_count = 0;
		}
		memcpy(&hdlc->state.fr.settings, &new_settings, size);
 
		hdlc->open = fr_open;
		hdlc->stop = fr_close;
		hdlc->netif_rx = fr_rx;
		hdlc->type_trans = NULL;
		hdlc->proto_detach = fr_destroy;
		hdlc->proto = IF_PROTO_FR;
		dev->hard_start_xmit = hdlc->xmit;
		dev->hard_header = NULL;
		dev->type = ARPHRD_FRAD;
		dev->flags = IFF_POINTOPOINT | IFF_NOARP;
		dev->addr_len = 0;
		return 0;
 
	case IF_PROTO_FR_ADD_PVC:
	case IF_PROTO_FR_DEL_PVC:
	case IF_PROTO_FR_ADD_ETH_PVC:
	case IF_PROTO_FR_DEL_ETH_PVC:
		if(!capable(CAP_NET_ADMIN))
			return -EPERM;
 
		if (copy_from_user(&pvc, ifr->ifr_settings.ifs_ifsu.fr_pvc,
				   sizeof(fr_proto_pvc)))
			return -EFAULT;
 
		if (pvc.dlci <= 0 || pvc.dlci >= 1024)
			return -EINVAL;	/* Only 10 bits, DLCI 0 reserved */
 
		if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC ||
		    ifr->ifr_settings.type == IF_PROTO_FR_DEL_ETH_PVC)
			result = ARPHRD_ETHER; /* bridged Ethernet device */
		else
			result = ARPHRD_DLCI;
 
		if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_PVC ||
		    ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC)
			return fr_add_pvc(hdlc, pvc.dlci, result);
		else
			return fr_del_pvc(hdlc, pvc.dlci, result);
	}
 
	return -EINVAL;
}