isdn_ppp.c

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/* $Id: isdn_ppp.c,v 1.85 2000/11/25 17:00:59 kai Exp $
 *
 * Linux ISDN subsystem, functions for synchronous PPP (linklevel).
 *
 * Copyright 1995,96 by Michael Hipp ([e-mail])
 *
 * 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, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <linux/config.h>
#define __NO_VERSION__
#include <linux/module.h>
#include <linux/version.h>
#include <linux/poll.h>
#include <linux/isdn.h>
#include <linux/ppp-comp.h>

#include "isdn_common.h"
#include "isdn_ppp.h"
#include "isdn_net.h"

#ifndef PPP_IPX
#define PPP_IPX 0x002b
#endif

/* Prototypes */
static int isdn_ppp_fill_rq(unsigned char *buf, int len, int proto, int slot);
static int isdn_ppp_closewait(int slot);
static void isdn_ppp_push_higher(isdn_net_dev * net_dev, isdn_net_local * lp,
				 struct sk_buff *skb, int proto);
static int isdn_ppp_if_get_unit(char *namebuf);
static int isdn_ppp_set_compressor(struct ippp_struct *is,struct isdn_ppp_comp_data *);
static struct sk_buff *isdn_ppp_decompress(struct sk_buff *,
				struct ippp_struct *,struct ippp_struct *,int *proto);
static void isdn_ppp_receive_ccp(isdn_net_dev * net_dev, isdn_net_local * lp,
				struct sk_buff *skb,int proto);
static struct sk_buff *isdn_ppp_compress(struct sk_buff *skb_in,int *proto,
	struct ippp_struct *is,struct ippp_struct *master,int type);
static void isdn_ppp_send_ccp(isdn_net_dev *net_dev, isdn_net_local *lp,
	 struct sk_buff *skb);

/* New CCP stuff */
static void isdn_ppp_ccp_kickup(struct ippp_struct *is);
static void isdn_ppp_ccp_xmit_reset(struct ippp_struct *is, int proto,
				    unsigned char code, unsigned char id,
				    unsigned char *data, int len);
static struct ippp_ccp_reset *isdn_ppp_ccp_reset_alloc(struct ippp_struct *is);
static void isdn_ppp_ccp_reset_free(struct ippp_struct *is);
static void isdn_ppp_ccp_reset_free_state(struct ippp_struct *is,
					  unsigned char id);
static void isdn_ppp_ccp_timer_callback(unsigned long closure);
static struct ippp_ccp_reset_state *isdn_ppp_ccp_reset_alloc_state(struct ippp_struct *is,
						      unsigned char id);
static void isdn_ppp_ccp_reset_trans(struct ippp_struct *is,
				     struct isdn_ppp_resetparams *rp);
static void isdn_ppp_ccp_reset_ack_rcvd(struct ippp_struct *is,
					unsigned char id);



#ifdef CONFIG_ISDN_MPP
static ippp_bundle * isdn_ppp_bundle_arr = NULL;
 
static int isdn_ppp_mp_bundle_array_init(void);
static int isdn_ppp_mp_init( isdn_net_local * lp, ippp_bundle * add_to );
static void isdn_ppp_mp_receive(isdn_net_dev * net_dev, isdn_net_local * lp, 
							struct sk_buff *skb);
static void isdn_ppp_mp_cleanup( isdn_net_local * lp );

static int isdn_ppp_bundle(struct ippp_struct *, int unit);
#endif	/* CONFIG_ISDN_MPP */
  
char *isdn_ppp_revision = "$Revision: 1.85 $";

static struct ippp_struct *ippp_table[ISDN_MAX_CHANNELS];

static struct isdn_ppp_compressor *ipc_head = NULL;

/*
 * frame log (debug)
 */
static void
isdn_ppp_frame_log(char *info, char *data, int len, int maxlen,int unit,int slot)
{
	int cnt,
	 j,
	 i;
	char buf[80];

	if (len < maxlen)
		maxlen = len;

	for (i = 0, cnt = 0; cnt < maxlen; i++) {
		for (j = 0; j < 16 && cnt < maxlen; j++, cnt++)
			sprintf(buf + j * 3, "%02x ", (unsigned char) data[cnt]);
		printk(KERN_DEBUG "[%d/%d].%s[%d]: %s\n",unit,slot, info, i, buf);
	}
}

/*
 * unbind isdn_net_local <=> ippp-device
 * note: it can happen, that we hangup/free the master before the slaves
 *       in this case we bind another lp to the master device
 */
int
isdn_ppp_free(isdn_net_local * lp)
{
	unsigned long flags;
	struct ippp_struct *is;

	if (lp->ppp_slot < 0 || lp->ppp_slot > ISDN_MAX_CHANNELS)
		return 0;

	save_flags(flags);
	cli();

#ifdef CONFIG_ISDN_MPP
	spin_lock(&lp->netdev->pb->lock);
#endif
	isdn_net_rm_from_bundle(lp);
#ifdef CONFIG_ISDN_MPP
	if (lp->netdev->pb->ref_ct == 1)	/* last link in queue? */
		isdn_ppp_mp_cleanup(lp);

	lp->netdev->pb->ref_ct--;
	spin_unlock(&lp->netdev->pb->lock);
#endif /* CONFIG_ISDN_MPP */

	is = ippp_table[lp->ppp_slot];
	if ((is->state & IPPP_CONNECT))
		isdn_ppp_closewait(lp->ppp_slot);	/* force wakeup on ippp device */
	else if (is->state & IPPP_ASSIGNED)
		is->state = IPPP_OPEN;	/* fallback to 'OPEN but not ASSIGNED' state */

	if (is->debug & 0x1)
		printk(KERN_DEBUG "isdn_ppp_free %d %lx %lx\n", lp->ppp_slot, (long) lp, (long) is->lp);

	is->lp = NULL;          /* link is down .. set lp to NULL */
	lp->ppp_slot = -1;      /* is this OK ?? */

	restore_flags(flags);
	return 0;
}

/*
 * bind isdn_net_local <=> ippp-device
 */
int
isdn_ppp_bind(isdn_net_local * lp)
{
	int i;
	int unit = 0;
	long flags;
	struct ippp_struct *is;

	save_flags(flags);
	cli();
	if (lp->pppbind < 0) {  /* device bounded to ippp device ? */
		isdn_net_dev *net_dev = dev->netdev;
		char exclusive[ISDN_MAX_CHANNELS];	/* exclusive flags */
		memset(exclusive, 0, ISDN_MAX_CHANNELS);
		while (net_dev) {	/* step through net devices to find exclusive minors */
			isdn_net_local *lp = net_dev->local;
			if (lp->pppbind >= 0)
				exclusive[lp->pppbind] = 1;
			net_dev = net_dev->next;
		}
		/*
		 * search a free device / slot
		 */
		for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
			if (ippp_table[i]->state == IPPP_OPEN && !exclusive[ippp_table[i]->minor]) {	/* OPEN, but not connected! */
				break;
			}
		}
	} else {
		for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
			if (ippp_table[i]->minor == lp->pppbind &&
			    (ippp_table[i]->state & IPPP_OPEN) == IPPP_OPEN)
				break;
		}
	}

	if (i >= ISDN_MAX_CHANNELS) {
		restore_flags(flags);
		printk(KERN_WARNING "isdn_ppp_bind: Can't find a (free) connection to the ipppd daemon.\n");
		return -1;
	}
	unit = isdn_ppp_if_get_unit(lp->name);	/* get unit number from interface name .. ugly! */
	if (unit < 0) {
		printk(KERN_ERR "isdn_ppp_bind: illegal interface name %s.\n", lp->name);
		return -1;
	}
	
	lp->ppp_slot = i;
	is = ippp_table[i];
	is->lp = lp;
	is->unit = unit;
	is->state = IPPP_OPEN | IPPP_ASSIGNED;	/* assigned to a netdevice but not connected */
#ifdef CONFIG_ISDN_MPP
	if (isdn_ppp_mp_init(lp, NULL) < 0)
		return -ENOMEM;
#endif /* CONFIG_ISDN_MPP */

	restore_flags(flags);

	return lp->ppp_slot;
}

/*
 * kick the ipppd on the device
 * (wakes up daemon after B-channel connect)
 */

void
isdn_ppp_wakeup_daemon(isdn_net_local * lp)
{
	if (lp->ppp_slot < 0 || lp->ppp_slot >= ISDN_MAX_CHANNELS)
		return;

	ippp_table[lp->ppp_slot]->state = IPPP_OPEN | IPPP_CONNECT | IPPP_NOBLOCK;

		wake_up_interruptible(&ippp_table[lp->ppp_slot]->wq);
}

/*
 * there was a hangup on the netdevice
 * force wakeup of the ippp device
 * go into 'device waits for release' state
 */
static int
isdn_ppp_closewait(int slot)
{
	struct ippp_struct *is;

	if (slot < 0 || slot >= ISDN_MAX_CHANNELS)
		return 0;
	is = ippp_table[slot];

	if (is->state)
		wake_up_interruptible(&is->wq);

	is->state = IPPP_CLOSEWAIT;
	return 1;
}

/*
 * isdn_ppp_find_slot / isdn_ppp_free_slot
 */

static int
isdn_ppp_get_slot(void)
{
	int i;
	for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
		if (!ippp_table[i]->state)
			return i;
	}
	return -1;
}

/*
 * isdn_ppp_open
 */

int
isdn_ppp_open(int min, struct file *file)
{
	int slot;
	struct ippp_struct *is;

	if (min < 0 || min > ISDN_MAX_CHANNELS)
		return -ENODEV;

	slot = isdn_ppp_get_slot();
	if (slot < 0) {
		return -EBUSY;
	}
	is = file->private_data = ippp_table[slot];

		printk(KERN_DEBUG "ippp, open, slot: %d, minor: %d, state: %04x\n", slot, min, is->state);

	/* compression stuff */
	is->link_compressor   = is->compressor = NULL;
	is->link_decompressor = is->decompressor = NULL;
	is->link_comp_stat    = is->comp_stat = NULL;
	is->link_decomp_stat  = is->decomp_stat = NULL;
	is->compflags = 0;

	is->reset = isdn_ppp_ccp_reset_alloc(is);

	is->lp = NULL;
	is->mp_seqno = 0;       /* MP sequence number */
	is->pppcfg = 0;         /* ppp configuration */
	is->mpppcfg = 0;        /* mppp configuration */
	is->last_link_seqno = -1;	/* MP: maybe set to Bundle-MIN, when joining a bundle ?? */
	is->unit = -1;          /* set, when we have our interface */
	is->mru = 1524;         /* MRU, default 1524 */
	is->maxcid = 16;        /* VJ: maxcid */
	is->tk = current;
	init_waitqueue_head(&is->wq);
	is->first = is->rq + NUM_RCV_BUFFS - 1;	/* receive queue */
	is->last = is->rq;
	is->minor = min;
#ifdef CONFIG_ISDN_PPP_VJ
	/*
	 * VJ header compression init
	 */
	is->slcomp = slhc_init(16, 16);	/* not necessary for 2. link in bundle */
#endif

	is->state = IPPP_OPEN;

	return 0;
}

/*
 * release ippp device
 */
void
isdn_ppp_release(int min, struct file *file)
{
	int i;
	struct ippp_struct *is;

	if (min < 0 || min >= ISDN_MAX_CHANNELS)
		return;
	is = file->private_data;

	if (is->debug & 0x1)
		printk(KERN_DEBUG "ippp: release, minor: %d %lx\n", min, (long) is->lp);

	if (is->lp) {           /* a lp address says: this link is still up */
		isdn_net_dev *p = is->lp->netdev;

		is->state &= ~IPPP_CONNECT;	/* -> effect: no call of wakeup */
		/*
		 * isdn_net_hangup() calls isdn_ppp_free()
		 * isdn_ppp_free() sets is->lp to NULL and lp->ppp_slot to -1
		 * removing the IPPP_CONNECT flag omits calling of isdn_ppp_wakeup_daemon()
		 */
		isdn_net_hangup(&p->dev);
	}
	for (i = 0; i < NUM_RCV_BUFFS; i++) {
		if (is->rq[i].buf) {
			kfree(is->rq[i].buf);
			is->rq[i].buf = NULL;
		}
	}
	is->first = is->rq + NUM_RCV_BUFFS - 1;	/* receive queue */
	is->last = is->rq;

#ifdef CONFIG_ISDN_PPP_VJ
/* TODO: if this was the previous master: link the slcomp to the new master */
	slhc_free(is->slcomp);
	is->slcomp = NULL;
#endif

/* TODO: if this was the previous master: link the the stuff to the new master */
	if(is->comp_stat)
		is->compressor->free(is->comp_stat);
	if(is->link_comp_stat)
		is->link_compressor->free(is->link_comp_stat);
	if(is->link_decomp_stat)
		is->link_decompressor->free(is->link_decomp_stat);
	if(is->decomp_stat)
		is->decompressor->free(is->decomp_stat);
        is->compressor   = is->link_compressor   = NULL;
        is->decompressor = is->link_decompressor = NULL;
	is->comp_stat    = is->link_comp_stat    = NULL;
        is->decomp_stat  = is->link_decomp_stat  = NULL;

	/* Clean up if necessary */
	if(is->reset)
		isdn_ppp_ccp_reset_free(is);

	/* this slot is ready for new connections */
	is->state = 0;
}

/*
 * get_arg .. ioctl helper
 */
static int
get_arg(void *b, void *val, int len)
{
	if (len <= 0)
		len = sizeof(void *);
	if (copy_from_user((void *) val, b, len))
		return -EFAULT;
	return 0;
}

/*
 * set arg .. ioctl helper
 */
static int
set_arg(void *b, void *val,int len)
{
	if(len <= 0)
		len = sizeof(void *);
	if (copy_to_user(b, (void *) val, len))
		return -EFAULT;
	return 0;
}

/*
 * ippp device ioctl
 */
int
isdn_ppp_ioctl(int min, struct file *file, unsigned int cmd, unsigned long arg)
{
	unsigned long val;
	int r,i,j;
	struct ippp_struct *is;
	isdn_net_local *lp;
	struct isdn_ppp_comp_data data;

	is = (struct ippp_struct *) file->private_data;
	lp = is->lp;

	if (is->debug & 0x1)
		printk(KERN_DEBUG "isdn_ppp_ioctl: minor: %d cmd: %x state: %x\n", min, cmd, is->state);

	if (!(is->state & IPPP_OPEN))
		return -EINVAL;

	switch (cmd) {
		case PPPIOCBUNDLE:
#ifdef CONFIG_ISDN_MPP
			if (!(is->state & IPPP_CONNECT))
				return -EINVAL;
			if ((r = get_arg((void *) arg, &val, sizeof(val) )))
				return r;
			printk(KERN_DEBUG "iPPP-bundle: minor: %d, slave unit: %d, master unit: %d\n",
			       (int) min, (int) is->unit, (int) val);
			return isdn_ppp_bundle(is, val);
#else
			return -1;
#endif
			break;
		case PPPIOCGUNIT:	/* get ppp/isdn unit number */
			if ((r = set_arg((void *) arg, &is->unit, sizeof(is->unit) )))
				return r;
			break;
		case PPPIOCGIFNAME:
			if(!lp)
				return -EINVAL;
			if ((r = set_arg((void *) arg, lp->name, strlen(lp->name))))
				return r;
			break;
		case PPPIOCGMPFLAGS:	/* get configuration flags */
			if ((r = set_arg((void *) arg, &is->mpppcfg, sizeof(is->mpppcfg) )))
				return r;
			break;
		case PPPIOCSMPFLAGS:	/* set configuration flags */
			if ((r = get_arg((void *) arg, &val, sizeof(val) )))
				return r;
			is->mpppcfg = val;
			break;
		case PPPIOCGFLAGS:	/* get configuration flags */
			if ((r = set_arg((void *) arg, &is->pppcfg,sizeof(is->pppcfg) )))
				return r;
			break;
		case PPPIOCSFLAGS:	/* set configuration flags */
			if ((r = get_arg((void *) arg, &val, sizeof(val) ))) {
				return r;
			}
			if (val & SC_ENABLE_IP && !(is->pppcfg & SC_ENABLE_IP) && (is->state & IPPP_CONNECT)) {
				if (lp) {
					/* OK .. we are ready to send buffers */
					netif_wake_queue(&lp->netdev->dev);
				}
			}
			is->pppcfg = val;
			break;
		case PPPIOCGIDLE:	/* get idle time information */