/* * Generic HDLC support routines for Linux * * Copyright (C) 1999, 2000 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. * * Current status: *    - this is work in progress *    - not heavily tested on SMP *    - currently supported: *	* raw IP-in-HDLC *	* Cisco HDLC *	* Frame Relay with ANSI or CCITT LMI (both user and network side) *	* PPP (using syncppp.c) *	* X.25 * * Use sethdlc utility to set line parameters, protocol and PVCs */#include <linux/config.h>#include <linux/module.h>#include <linux/kernel.h>#include <linux/slab.h>#include <linux/poll.h>#include <linux/sched.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>/* #define DEBUG_PKT *//* #define DEBUG_HARD_HEADER *//* #define DEBUG_FECN *//* #define DEBUG_BECN */static const char* version = "HDLC support module revision 1.02 for Linux 2.4";#define CISCO_MULTICAST		0x8F	/* Cisco multicast address */#define CISCO_UNICAST		0x0F	/* Cisco unicast address */#define CISCO_KEEPALIVE		0x8035	/* Cisco keepalive protocol */#define CISCO_SYS_INFO		0x2000	/* Cisco interface/system info */#define CISCO_ADDR_REQ		0	/* Cisco address request */#define CISCO_ADDR_REPLY	1	/* Cisco address reply */#define CISCO_KEEPALIVE_REQ	2	/* Cisco keepalive request */static int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);/******************************************************** * * Cisco HDLC support * *******************************************************/static int cisco_hard_header(struct sk_buff *skb, struct net_device *dev,			     u16 type, void *daddr, void *saddr,			     unsigned int len){	hdlc_header *data;#ifdef DEBUG_HARD_HEADER	printk(KERN_DEBUG "%s: cisco_hard_header called\n", dev->name);#endif	skb_push(skb, sizeof(hdlc_header));	data = (hdlc_header*)skb->data;	if (type == CISCO_KEEPALIVE)		data->address = CISCO_MULTICAST;	else		data->address = CISCO_UNICAST;	data->control = 0;	data->protocol = htons(type);	return sizeof(hdlc_header);}static void cisco_keepalive_send(hdlc_device *hdlc, u32 type,				 u32 par1, u32 par2){	struct sk_buff *skb;	cisco_packet *data;	skb = dev_alloc_skb(sizeof(hdlc_header)+sizeof(cisco_packet));	if (!skb) {		printk(KERN_WARNING "%s: Memory squeeze on cisco_keepalive_send()\n",			       hdlc_to_name(hdlc));		return;	}	skb_reserve(skb, 4);	cisco_hard_header(skb, hdlc_to_dev(hdlc), CISCO_KEEPALIVE,			  NULL, NULL, 0);	data = (cisco_packet*)skb->tail;	data->type = htonl(type);	data->par1 = htonl(par1);	data->par2 = htonl(par2);	data->rel = 0xFFFF;	data->time = htonl(jiffies * 1000 / HZ);	skb_put(skb, sizeof(cisco_packet));	skb->priority = TC_PRIO_CONTROL;	skb->dev = hdlc_to_dev(hdlc);	dev_queue_xmit(skb);}static void cisco_netif(hdlc_device *hdlc, struct sk_buff *skb){	hdlc_header *data = (hdlc_header*)skb->data;	cisco_packet *cisco_data;	struct in_device *in_dev;	u32 addr, mask;	if (skb->len<sizeof(hdlc_header))		goto rx_error;	if (data->address != CISCO_MULTICAST &&	    data->address != CISCO_UNICAST)		goto rx_error;	skb_pull(skb, sizeof(hdlc_header));	switch(ntohs(data->protocol)) {	case ETH_P_IP:	case ETH_P_IPX:	case ETH_P_IPV6:		skb->protocol = data->protocol;		skb->dev = hdlc_to_dev(hdlc);		netif_rx(skb);		return;	case CISCO_SYS_INFO:		/* Packet is not needed, drop it. */		dev_kfree_skb_any(skb);		return;	case CISCO_KEEPALIVE:		if (skb->len != CISCO_PACKET_LEN &&		    skb->len != CISCO_BIG_PACKET_LEN) {			printk(KERN_INFO "%s: Invalid length of Cisco "			       "control packet (%d bytes)\n",			       hdlc_to_name(hdlc), skb->len);			goto rx_error;		}		cisco_data = (cisco_packet*)skb->data;		switch(ntohl (cisco_data->type)) {		case CISCO_ADDR_REQ: /* Stolen from syncppp.c :-) */			in_dev = hdlc_to_dev(hdlc)->ip_ptr;			addr = 0;			mask = ~0; /* is the mask correct? */			if (in_dev != NULL) {				struct in_ifaddr **ifap = &in_dev->ifa_list;				while (*ifap != NULL) {					if (strcmp(hdlc_to_name(hdlc),						   (*ifap)->ifa_label) == 0) {						addr = (*ifap)->ifa_local;						mask = (*ifap)->ifa_mask;						break;					}					ifap = &(*ifap)->ifa_next;				}				cisco_keepalive_send(hdlc, CISCO_ADDR_REPLY,						     addr, mask);			}			dev_kfree_skb_any(skb);			return;		case CISCO_ADDR_REPLY:			printk(KERN_INFO "%s: Unexpected Cisco IP address "			       "reply\n", hdlc_to_name(hdlc));			goto rx_error;		case CISCO_KEEPALIVE_REQ:			hdlc->lmi.rxseq = ntohl(cisco_data->par1);			if (ntohl(cisco_data->par2) == hdlc->lmi.txseq) {				hdlc->lmi.last_poll = jiffies;				if (!(hdlc->lmi.state & LINK_STATE_RELIABLE)) {					u32 sec, min, hrs, days;					sec = ntohl(cisco_data->time) / 1000;					min = sec / 60; sec -= min * 60;					hrs = min / 60; min -= hrs * 60;					days = hrs / 24; hrs -= days * 24;					printk(KERN_INFO "%s: Link up (peer "					       "uptime %ud%uh%um%us)\n",					       hdlc_to_name(hdlc), days, hrs,					       min, sec);				}				hdlc->lmi.state |= LINK_STATE_RELIABLE;			}			dev_kfree_skb_any(skb);			return;		} /* switch(keepalive type) */	} /* switch(protocol) */	printk(KERN_INFO "%s: Unsupported protocol %x\n", hdlc_to_name(hdlc),	       data->protocol);	dev_kfree_skb_any(skb);	return; rx_error:	hdlc->stats.rx_errors++; /* Mark error */	dev_kfree_skb_any(skb);}static void cisco_timer(unsigned long arg){	hdlc_device *hdlc = (hdlc_device*)arg;	if ((hdlc->lmi.state & LINK_STATE_RELIABLE) &&	    (jiffies - hdlc->lmi.last_poll >= hdlc->lmi.T392 * HZ)) {		hdlc->lmi.state &= ~LINK_STATE_RELIABLE;		printk(KERN_INFO "%s: Link down\n", hdlc_to_name(hdlc));	}	cisco_keepalive_send(hdlc, CISCO_KEEPALIVE_REQ, ++hdlc->lmi.txseq,			     hdlc->lmi.rxseq);	hdlc->timer.expires = jiffies + hdlc->lmi.T391*HZ;	hdlc->timer.function = cisco_timer;	hdlc->timer.data = arg;	add_timer(&hdlc->timer);}/****************************************************************** * *     generic Frame Relay routines * *****************************************************************/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 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 inline void fr_log_dlci_active(pvc_device *pvc){	printk(KERN_INFO "%s: %sactive%s\n", pvc_to_name(pvc),	       pvc->state & PVC_STATE_ACTIVE ? "" : "in",	       pvc->state & 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->first_pvc;	int len = mode_is(hdlc, MODE_FR_ANSI) ? LMI_ANSI_LENGTH : LMI_LENGTH;	int stat_len = 3;	u8 *data;	int i = 0;	if (mode_is(hdlc, MODE_DCE) && fullrep) {		len += hdlc->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++] = mode_is(hdlc, MODE_DCE) ? LMI_STATUS : LMI_STATUS_ENQUIRY;	if (mode_is(hdlc, MODE_FR_ANSI))		data[i++] = LMI_ANSI_LOCKSHIFT;	data[i++] = mode_is(hdlc, MODE_FR_CCITT) ? LMI_CCITT_REPTYPE :		LMI_REPTYPE;	data[i++] = LMI_REPT_LEN;	data[i++] = fullrep ? LMI_FULLREP : LMI_INTEGRITY;	data[i++] = mode_is(hdlc, MODE_FR_CCITT) ? LMI_CCITT_ALIVE : LMI_ALIVE;	data[i++] = LMI_INTEG_LEN;	data[i++] = hdlc->lmi.txseq = fr_lmi_nextseq(hdlc->lmi.txseq);	data[i++] = hdlc->lmi.rxseq;	if (mode_is(hdlc, MODE_DCE) && fullrep) {		while (pvc) {			data[i++] = mode_is(hdlc, MODE_FR_CCITT) ?				LMI_CCITT_PVCSTAT:LMI_PVCSTAT;			data[i++] = stat_len;			if ((hdlc->lmi.state & LINK_STATE_RELIABLE) &&			    (pvc->netdev.flags & IFF_UP) &&			    !(pvc->state & (PVC_STATE_ACTIVE|PVC_STATE_NEW))) {				pvc->state |= PVC_STATE_NEW;				fr_log_dlci_active(pvc);			}			dlci_to_status(hdlc, netdev_dlci(&pvc->netdev),				       data+i, pvc->state);			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 (mode_is(hdlc, MODE_DCE))		reliable = (jiffies - hdlc->lmi.last_poll < hdlc->lmi.T392*HZ);	else {		hdlc->lmi.last_errors <<= 1; /* Shift the list */		if (hdlc->lmi.state & LINK_STATE_REQUEST) {			printk(KERN_INFO "%s: No LMI status reply received\n",			       hdlc_to_name(hdlc));			hdlc->lmi.last_errors |= 1;		}		for (i = 0, list = hdlc->lmi.last_errors; i < hdlc->lmi.N393;		     i++, list >>= 1)			cnt += (list & 1);	/* errors count */		reliable = (cnt < hdlc->lmi.N392);	}	if ((hdlc->lmi.state & LINK_STATE_RELIABLE) !=	    (reliable ? LINK_STATE_RELIABLE : 0)) {		pvc_device *pvc = hdlc->first_pvc;		while (pvc) {/* Deactivate all PVCs */			pvc->state &= ~(PVC_STATE_NEW | PVC_STATE_ACTIVE);			pvc = pvc->next;		}		hdlc->lmi.state ^= LINK_STATE_RELIABLE;		printk(KERN_INFO "%s: Link %sreliable\n", hdlc_to_name(hdlc),		       reliable ? "" : "un");		if (reliable) {			hdlc->lmi.N391cnt = 0; /* Request full status */			hdlc->lmi.state |= LINK_STATE_CHANGED;		}	}	if (mode_is(hdlc, MODE_DCE))		hdlc->timer.expires = jiffies + hdlc->lmi.T392*HZ;	else {		if (hdlc->lmi.N391cnt)			hdlc->lmi.N391cnt--;		fr_lmi_send(hdlc, hdlc->lmi.N391cnt == 0);		hdlc->lmi.state |= LINK_STATE_REQUEST;		hdlc->timer.expires = jiffies + hdlc->lmi.T391*HZ;	}	hdlc->timer.function = fr_timer;	hdlc->timer.data = arg;	add_timer(&hdlc->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 < (mode_is(hdlc, MODE_FR_ANSI) ?			LMI_ANSI_LENGTH : LMI_LENGTH)) {		printk(KERN_INFO "%s: Short LMI frame\n", hdlc_to_name(hdlc));		return 1;	}	if (skb->data[5] != (!mode_is(hdlc, MODE_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],		       mode_is(hdlc, MODE_DCE) ? "enquiry" : "reply");		return 1;	}	i = mode_is(hdlc, MODE_FR_ANSI) ? 7 : 6;	if (skb->data[i] !=	    (mode_is(hdlc, MODE_FR_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 */