[people/ms/linux.git] / drivers / isdn / i4l / isdn_x25iface.c

/* $Id: isdn_x25iface.c,v 1.1.2.2 2004/01/12 22:37:19 keil Exp $
 *
 * Linux ISDN subsystem, X.25 related functions
 *
 * This software may be used and distributed according to the terms
 * of the GNU General Public License, incorporated herein by reference.
 *
 * stuff needed to support the Linux X.25 PLP code on top of devices that
 * can provide a lab_b service using the concap_proto mechanism.
 * This module supports a network interface which provides lapb_sematics
 * -- as defined in Documentation/networking/x25-iface.txt -- to
 * the upper layer and assumes that the lower layer provides a reliable
 * data link service by means of the concap_device_ops callbacks.
 *
 * Only protocol specific stuff goes here. Device specific stuff
 * goes to another -- device related -- concap_proto support source file.
 *
 */

/* #include <linux/isdn.h> */
#include <linux/netdevice.h>
#include <linux/concap.h>
#include <linux/slab.h>
#include <linux/wanrouter.h>
#include <net/x25device.h>
#include "isdn_x25iface.h"

/* for debugging messages not to cause an oops when device pointer is NULL*/
#define MY_DEVNAME(dev)  ((dev) ? (dev)->name : "DEVICE UNSPECIFIED")


typedef struct isdn_x25iface_proto_data {
	int magic;
	enum wan_states state;
	/* Private stuff, not to be accessed via proto_data. We provide the
	   other storage for the concap_proto instance here as well,
	   enabling us to allocate both with just one kmalloc(): */
	struct concap_proto priv;
} ix25_pdata_t;


/* is now in header file (extern): struct concap_proto * isdn_x25iface_proto_new(void); */
static void isdn_x25iface_proto_del(struct concap_proto *);
static int isdn_x25iface_proto_close(struct concap_proto *);
static int isdn_x25iface_proto_restart(struct concap_proto *,
				       struct net_device *,
				       struct concap_device_ops *);
static int isdn_x25iface_xmit(struct concap_proto *, struct sk_buff *);
static int isdn_x25iface_receive(struct concap_proto *, struct sk_buff *);
static int isdn_x25iface_connect_ind(struct concap_proto *);
static int isdn_x25iface_disconn_ind(struct concap_proto *);


static struct concap_proto_ops ix25_pops = {
	.proto_new = &isdn_x25iface_proto_new,
	.proto_del = &isdn_x25iface_proto_del,
	.restart = &isdn_x25iface_proto_restart,
	.close = &isdn_x25iface_proto_close,
	.encap_and_xmit = &isdn_x25iface_xmit,
	.data_ind = &isdn_x25iface_receive,
	.connect_ind = &isdn_x25iface_connect_ind,
	.disconn_ind = &isdn_x25iface_disconn_ind
};

/* error message helper function */
static void illegal_state_warn(unsigned state, unsigned char firstbyte)
{
	printk(KERN_WARNING "isdn_x25iface: firstbyte %x illegal in"
	       "current state %d\n", firstbyte, state);
}

/* check protocol data field for consistency */
static int pdata_is_bad(ix25_pdata_t *pda) {

	if (pda  &&  pda->magic == ISDN_X25IFACE_MAGIC) return 0;
	printk(KERN_WARNING
	       "isdn_x25iface_xxx: illegal pointer to proto data\n");
	return 1;
}

/* create a new x25 interface protocol instance
 */
struct concap_proto *isdn_x25iface_proto_new(void)
{
	ix25_pdata_t *tmp = kmalloc(sizeof(ix25_pdata_t), GFP_KERNEL);
	IX25DEBUG("isdn_x25iface_proto_new\n");
	if (tmp) {
		tmp->magic = ISDN_X25IFACE_MAGIC;
		tmp->state = WAN_UNCONFIGURED;
		/* private data space used to hold the concap_proto data.
		   Only to be accessed via the returned pointer */
		spin_lock_init(&tmp->priv.lock);
		tmp->priv.dops       = NULL;
		tmp->priv.net_dev    = NULL;
		tmp->priv.pops       = &ix25_pops;
		tmp->priv.flags      = 0;
		tmp->priv.proto_data = tmp;
		return (&(tmp->priv));
	}
	return NULL;
};

/* close the x25iface encapsulation protocol
 */
static int isdn_x25iface_proto_close(struct concap_proto *cprot) {

	ix25_pdata_t *tmp;
	int ret = 0;
	ulong flags;

	if (!cprot) {
		printk(KERN_ERR "isdn_x25iface_proto_close: "
		       "invalid concap_proto pointer\n");
		return -1;
	}
	IX25DEBUG("isdn_x25iface_proto_close %s \n", MY_DEVNAME(cprot->net_dev));
	spin_lock_irqsave(&cprot->lock, flags);
	cprot->dops    = NULL;
	cprot->net_dev = NULL;
	tmp = cprot->proto_data;
	if (pdata_is_bad(tmp)) {
		ret = -1;
	} else {
		tmp->state = WAN_UNCONFIGURED;
	}
	spin_unlock_irqrestore(&cprot->lock, flags);
	return ret;
}

/* Delete the x25iface encapsulation protocol instance
 */
static void isdn_x25iface_proto_del(struct concap_proto *cprot) {

	ix25_pdata_t *tmp;

	IX25DEBUG("isdn_x25iface_proto_del \n");
	if (!cprot) {
		printk(KERN_ERR "isdn_x25iface_proto_del: "
		       "concap_proto pointer is NULL\n");
		return;
	}
	tmp = cprot->proto_data;
	if (tmp == NULL) {
		printk(KERN_ERR "isdn_x25iface_proto_del: inconsistent "
		       "proto_data pointer (maybe already deleted?)\n");
		return;
	}
	/* close if the protocol is still open */
	if (cprot->dops) isdn_x25iface_proto_close(cprot);
	/* freeing the storage should be sufficient now. But some additional
	   settings might help to catch wild pointer bugs */
	tmp->magic = 0;
	cprot->proto_data = NULL;

	kfree(tmp);
	return;
}

/* (re-)initialize the data structures for x25iface encapsulation
 */
static int isdn_x25iface_proto_restart(struct concap_proto *cprot,
				       struct net_device *ndev,
				       struct concap_device_ops *dops)
{
	ix25_pdata_t *pda = cprot->proto_data;
	ulong flags;

	IX25DEBUG("isdn_x25iface_proto_restart %s \n", MY_DEVNAME(ndev));

	if (pdata_is_bad(pda)) return -1;

	if (!(dops && dops->data_req && dops->connect_req
	      && dops->disconn_req)) {
		printk(KERN_WARNING "isdn_x25iface_restart: required dops"
		       " missing\n");
		isdn_x25iface_proto_close(cprot);
		return -1;
	}
	spin_lock_irqsave(&cprot->lock, flags);
	cprot->net_dev = ndev;
	cprot->pops = &ix25_pops;
	cprot->dops = dops;
	pda->state = WAN_DISCONNECTED;
	spin_unlock_irqrestore(&cprot->lock, flags);
	return 0;
}

/* deliver a dl_data frame received from i4l HL driver to the network layer
 */
static int isdn_x25iface_receive(struct concap_proto *cprot, struct sk_buff *skb)
{
	IX25DEBUG("isdn_x25iface_receive %s \n", MY_DEVNAME(cprot->net_dev));
	if (((ix25_pdata_t *)(cprot->proto_data))
	    ->state == WAN_CONNECTED) {
		if (skb_push(skb, 1)) {
			skb->data[0] = X25_IFACE_DATA;
			skb->protocol = x25_type_trans(skb, cprot->net_dev);
			netif_rx(skb);
			return 0;
		}
	}
	printk(KERN_WARNING "isdn_x25iface_receive %s: not connected, skb dropped\n", MY_DEVNAME(cprot->net_dev));
	dev_kfree_skb(skb);
	return -1;
}

/* a connection set up is indicated by lower layer
 */
static int isdn_x25iface_connect_ind(struct concap_proto *cprot)
{
	struct sk_buff *skb;
	enum wan_states *state_p
		= &(((ix25_pdata_t *)(cprot->proto_data))->state);
	IX25DEBUG("isdn_x25iface_connect_ind %s \n"
		  , MY_DEVNAME(cprot->net_dev));
	if (*state_p == WAN_UNCONFIGURED) {
		printk(KERN_WARNING
		       "isdn_x25iface_connect_ind while unconfigured %s\n"
		       , MY_DEVNAME(cprot->net_dev));
		return -1;
	}
	*state_p = WAN_CONNECTED;

	skb = dev_alloc_skb(1);
	if (skb) {
		*(skb_put(skb, 1)) = X25_IFACE_CONNECT;
		skb->protocol = x25_type_trans(skb, cprot->net_dev);
		netif_rx(skb);
		return 0;
	} else {
		printk(KERN_WARNING "isdn_x25iface_connect_ind: "
		       " out of memory -- disconnecting\n");
		cprot->dops->disconn_req(cprot);
		return -1;
	}
}

/* a disconnect is indicated by lower layer
 */
static int isdn_x25iface_disconn_ind(struct concap_proto *cprot)
{
	struct sk_buff *skb;
	enum wan_states *state_p
		= &(((ix25_pdata_t *)(cprot->proto_data))->state);
	IX25DEBUG("isdn_x25iface_disconn_ind %s \n", MY_DEVNAME(cprot->net_dev));
	if (*state_p == WAN_UNCONFIGURED) {
		printk(KERN_WARNING
		       "isdn_x25iface_disconn_ind while unconfigured\n");
		return -1;
	}
	if (!cprot->net_dev) return -1;
	*state_p = WAN_DISCONNECTED;
	skb = dev_alloc_skb(1);
	if (skb) {
		*(skb_put(skb, 1)) = X25_IFACE_DISCONNECT;
		skb->protocol = x25_type_trans(skb, cprot->net_dev);
		netif_rx(skb);
		return 0;
	} else {
		printk(KERN_WARNING "isdn_x25iface_disconn_ind:"
		       " out of memory\n");
		return -1;
	}
}

/* process a frame handed over to us from linux network layer. First byte
   semantics as defined in Documentation/networking/x25-iface.txt
*/
static int isdn_x25iface_xmit(struct concap_proto *cprot, struct sk_buff *skb)
{
	unsigned char firstbyte = skb->data[0];
	enum wan_states *state = &((ix25_pdata_t *)cprot->proto_data)->state;
	int ret = 0;
	IX25DEBUG("isdn_x25iface_xmit: %s first=%x state=%d\n",
		  MY_DEVNAME(cprot->net_dev), firstbyte, *state);
	switch (firstbyte) {
	case X25_IFACE_DATA:
		if (*state == WAN_CONNECTED) {
			skb_pull(skb, 1);
			cprot->net_dev->trans_start = jiffies;
			ret = (cprot->dops->data_req(cprot, skb));
			/* prepare for future retransmissions */
			if (ret) skb_push(skb, 1);
			return ret;
		}
		illegal_state_warn(*state, firstbyte);
		break;
	case X25_IFACE_CONNECT:
		if (*state == WAN_DISCONNECTED) {
			*state = WAN_CONNECTING;
			ret = cprot->dops->connect_req(cprot);
			if (ret) {
				/* reset state and notify upper layer about
				 * immidiatly failed attempts */
				isdn_x25iface_disconn_ind(cprot);
			}
		} else {
			illegal_state_warn(*state, firstbyte);
		}
		break;
	case X25_IFACE_DISCONNECT:
		switch (*state) {
		case WAN_DISCONNECTED:
			/* Should not happen. However, give upper layer a
			   chance to recover from inconstistency  but don't
			   trust the lower layer sending the disconn_confirm
			   when already disconnected */
			printk(KERN_WARNING "isdn_x25iface_xmit: disconnect "
			       " requested while disconnected\n");
			isdn_x25iface_disconn_ind(cprot);
			break; /* prevent infinite loops */
		case WAN_CONNECTING:
		case WAN_CONNECTED:
			*state = WAN_DISCONNECTED;
			cprot->dops->disconn_req(cprot);
			break;
		default:
			illegal_state_warn(*state, firstbyte);
		}
		break;
	case X25_IFACE_PARAMS:
		printk(KERN_WARNING "isdn_x25iface_xmit: setting of lapb"
		       " options not yet supported\n");
		break;
	default:
		printk(KERN_WARNING "isdn_x25iface_xmit: frame with illegal"
		       " first byte %x ignored:\n", firstbyte);
	}
	dev_kfree_skb(skb);
	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/* $Id: isdn_x25iface.c,v 1.1.2.2 2004/01/12 22:37:19 keil Exp $
	2	*
	3	* Linux ISDN subsystem, X.25 related functions
	4	*
	5	* This software may be used and distributed according to the terms
	6	* of the GNU General Public License, incorporated herein by reference.
	7	*
	8	* stuff needed to support the Linux X.25 PLP code on top of devices that
	9	* can provide a lab_b service using the concap_proto mechanism.
c30fe7f7	10	* This module supports a network interface which provides lapb_sematics
1da177e4 LT	11	* -- as defined in Documentation/networking/x25-iface.txt -- to
	12	* the upper layer and assumes that the lower layer provides a reliable
	13	* data link service by means of the concap_device_ops callbacks.
	14	*
	15	* Only protocol specific stuff goes here. Device specific stuff
	16	* goes to another -- device related -- concap_proto support source file.
	17	*
	18	*/
	19
	20	/* #include <linux/isdn.h> */
	21	#include <linux/netdevice.h>
	22	#include <linux/concap.h>
5a0e3ad6	23	#include <linux/slab.h>
1da177e4 LT	24	#include <linux/wanrouter.h>
	25	#include <net/x25device.h>
	26	#include "isdn_x25iface.h"
	27
	28	/* for debugging messages not to cause an oops when device pointer is NULL*/
475be4d8	29	#define MY_DEVNAME(dev) ((dev) ? (dev)->name : "DEVICE UNSPECIFIED")
1da177e4 LT	30
	31
	32	typedef struct isdn_x25iface_proto_data {
	33	int magic;
	34	enum wan_states state;
	35	/* Private stuff, not to be accessed via proto_data. We provide the
	36	other storage for the concap_proto instance here as well,
475be4d8	37	enabling us to allocate both with just one kmalloc(): */
1da177e4 LT	38	struct concap_proto priv;
	39	} ix25_pdata_t;
	40
	41
	42
	43	/* is now in header file (extern): struct concap_proto * isdn_x25iface_proto_new(void); */
475be4d8 JP	44	static void isdn_x25iface_proto_del(struct concap_proto *);
	45	static int isdn_x25iface_proto_close(struct concap_proto *);
	46	static int isdn_x25iface_proto_restart(struct concap_proto *,
	47	struct net_device *,
	48	struct concap_device_ops *);
	49	static int isdn_x25iface_xmit(struct concap_proto , struct sk_buff );
	50	static int isdn_x25iface_receive(struct concap_proto , struct sk_buff );
	51	static int isdn_x25iface_connect_ind(struct concap_proto *);
	52	static int isdn_x25iface_disconn_ind(struct concap_proto *);
1da177e4 LT	53
	54
	55	static struct concap_proto_ops ix25_pops = {
63d9c273 MT	56	.proto_new = &isdn_x25iface_proto_new,
	57	.proto_del = &isdn_x25iface_proto_del,
	58	.restart = &isdn_x25iface_proto_restart,
	59	.close = &isdn_x25iface_proto_close,
	60	.encap_and_xmit = &isdn_x25iface_xmit,
	61	.data_ind = &isdn_x25iface_receive,
	62	.connect_ind = &isdn_x25iface_connect_ind,
	63	.disconn_ind = &isdn_x25iface_disconn_ind
1da177e4 LT	64	};
	65
	66	/* error message helper function */
475be4d8	67	static void illegal_state_warn(unsigned state, unsigned char firstbyte)
1da177e4	68	{
475be4d8 JP	69	printk(KERN_WARNING "isdn_x25iface: firstbyte %x illegal in"
475be4d8 JP	70	"current state %d\n", firstbyte, state);
1da177e4 LT	71	}
	72
	73	/* check protocol data field for consistency */
475be4d8	74	static int pdata_is_bad(ix25_pdata_t *pda) {
1da177e4	75
475be4d8 JP	76	if (pda && pda->magic == ISDN_X25IFACE_MAGIC) return 0;
	77	printk(KERN_WARNING
	78	"isdn_x25iface_xxx: illegal pointer to proto data\n");
1da177e4 LT	79	return 1;
	80	}
	81
	82	/* create a new x25 interface protocol instance
	83	*/
475be4d8	84	struct concap_proto *isdn_x25iface_proto_new(void)
1da177e4	85	{
475be4d8	86	ix25_pdata_t *tmp = kmalloc(sizeof(ix25_pdata_t), GFP_KERNEL);
1da177e4	87	IX25DEBUG("isdn_x25iface_proto_new\n");
475be4d8 JP	88	if (tmp) {
	89	tmp->magic = ISDN_X25IFACE_MAGIC;
	90	tmp->state = WAN_UNCONFIGURED;
1da177e4 LT	91	/* private data space used to hold the concap_proto data.
	92	Only to be accessed via the returned pointer */
	93	spin_lock_init(&tmp->priv.lock);
475be4d8 JP	94	tmp->priv.dops = NULL;
	95	tmp->priv.net_dev = NULL;
	96	tmp->priv.pops = &ix25_pops;
	97	tmp->priv.flags = 0;
	98	tmp->priv.proto_data = tmp;
	99	return (&(tmp->priv));
1da177e4 LT	100	}
	101	return NULL;
	102	};
	103
475be4d8	104	/* close the x25iface encapsulation protocol
1da177e4	105	*/
475be4d8	106	static int isdn_x25iface_proto_close(struct concap_proto *cprot) {
1da177e4 LT	107
1da177e4 LT	108	ix25_pdata_t *tmp;
475be4d8	109	int ret = 0;
1da177e4 LT	110	ulong flags;
1da177e4 LT	111
475be4d8 JP	112	if (!cprot) {
	113	printk(KERN_ERR "isdn_x25iface_proto_close: "
	114	"invalid concap_proto pointer\n");
1da177e4 LT	115	return -1;
1da177e4 LT	116	}
475be4d8	117	IX25DEBUG("isdn_x25iface_proto_close %s \n", MY_DEVNAME(cprot->net_dev));
1da177e4	118	spin_lock_irqsave(&cprot->lock, flags);
475be4d8 JP	119	cprot->dops = NULL;
	120	cprot->net_dev = NULL;
	121	tmp = cprot->proto_data;
	122	if (pdata_is_bad(tmp)) {
1da177e4 LT	123	ret = -1;
1da177e4 LT	124	} else {
475be4d8	125	tmp->state = WAN_UNCONFIGURED;
1da177e4 LT	126	}
	127	spin_unlock_irqrestore(&cprot->lock, flags);
	128	return ret;
	129	}
	130
	131	/* Delete the x25iface encapsulation protocol instance
	132	*/
475be4d8 JP	133	static void isdn_x25iface_proto_del(struct concap_proto *cprot) {
	134
	135	ix25_pdata_t *tmp;
1da177e4	136
475be4d8 JP	137	IX25DEBUG("isdn_x25iface_proto_del \n");
	138	if (!cprot) {
	139	printk(KERN_ERR "isdn_x25iface_proto_del: "
	140	"concap_proto pointer is NULL\n");
1da177e4 LT	141	return;
1da177e4 LT	142	}
475be4d8 JP	143	tmp = cprot->proto_data;
	144	if (tmp == NULL) {
	145	printk(KERN_ERR "isdn_x25iface_proto_del: inconsistent "
	146	"proto_data pointer (maybe already deleted?)\n");
1da177e4 LT	147	return;
	148	}
	149	/* close if the protocol is still open */
475be4d8	150	if (cprot->dops) isdn_x25iface_proto_close(cprot);
1da177e4 LT	151	/* freeing the storage should be sufficient now. But some additional
1da177e4 LT	152	settings might help to catch wild pointer bugs */
475be4d8 JP	153	tmp->magic = 0;
475be4d8 JP	154	cprot->proto_data = NULL;
1da177e4	155
475be4d8	156	kfree(tmp);
1da177e4 LT	157	return;
	158	}
	159
	160	/* (re-)initialize the data structures for x25iface encapsulation
	161	*/
3e206b0a	162	static int isdn_x25iface_proto_restart(struct concap_proto *cprot,
475be4d8 JP	163	struct net_device *ndev,
475be4d8 JP	164	struct concap_device_ops *dops)
1da177e4	165	{
475be4d8	166	ix25_pdata_t *pda = cprot->proto_data;
1da177e4 LT	167	ulong flags;
1da177e4 LT	168
475be4d8	169	IX25DEBUG("isdn_x25iface_proto_restart %s \n", MY_DEVNAME(ndev));
1da177e4	170
475be4d8	171	if (pdata_is_bad(pda)) return -1;
1da177e4	172
475be4d8 JP	173	if (!(dops && dops->data_req && dops->connect_req
	174	&& dops->disconn_req)) {
	175	printk(KERN_WARNING "isdn_x25iface_restart: required dops"
	176	" missing\n");
1da177e4 LT	177	isdn_x25iface_proto_close(cprot);
	178	return -1;
	179	}
	180	spin_lock_irqsave(&cprot->lock, flags);
475be4d8 JP	181	cprot->net_dev = ndev;
	182	cprot->pops = &ix25_pops;
	183	cprot->dops = dops;
	184	pda->state = WAN_DISCONNECTED;
1da177e4 LT	185	spin_unlock_irqrestore(&cprot->lock, flags);
	186	return 0;
	187	}
	188
475be4d8	189	/* deliver a dl_data frame received from i4l HL driver to the network layer
1da177e4	190	*/
3e206b0a	191	static int isdn_x25iface_receive(struct concap_proto cprot, struct sk_buff skb)
1da177e4	192	{
475be4d8 JP	193	IX25DEBUG("isdn_x25iface_receive %s \n", MY_DEVNAME(cprot->net_dev));
	194	if (((ix25_pdata_t *)(cprot->proto_data))
	195	->state == WAN_CONNECTED) {
	196	if (skb_push(skb, 1)) {
4150bbf3	197	skb->data[0] = X25_IFACE_DATA;
1da177e4 LT	198	skb->protocol = x25_type_trans(skb, cprot->net_dev);
	199	netif_rx(skb);
	200	return 0;
	201	}
	202	}
475be4d8	203	printk(KERN_WARNING "isdn_x25iface_receive %s: not connected, skb dropped\n", MY_DEVNAME(cprot->net_dev));
1da177e4 LT	204	dev_kfree_skb(skb);
	205	return -1;
	206	}
	207
475be4d8	208	/* a connection set up is indicated by lower layer
1da177e4	209	*/
3e206b0a	210	static int isdn_x25iface_connect_ind(struct concap_proto *cprot)
1da177e4	211	{
475be4d8 JP	212	struct sk_buff *skb;
	213	enum wan_states *state_p
	214	= &(((ix25_pdata_t *)(cprot->proto_data))->state);
	215	IX25DEBUG("isdn_x25iface_connect_ind %s \n"
	216	, MY_DEVNAME(cprot->net_dev));
	217	if (*state_p == WAN_UNCONFIGURED) {
	218	printk(KERN_WARNING
1da177e4	219	"isdn_x25iface_connect_ind while unconfigured %s\n"
475be4d8	220	, MY_DEVNAME(cprot->net_dev));
1da177e4 LT	221	return -1;
	222	}
	223	*state_p = WAN_CONNECTED;
d81931d9 ES	224
d81931d9 ES	225	skb = dev_alloc_skb(1);
475be4d8	226	if (skb) {
4150bbf3	227	*(skb_put(skb, 1)) = X25_IFACE_CONNECT;
1da177e4 LT	228	skb->protocol = x25_type_trans(skb, cprot->net_dev);
	229	netif_rx(skb);
	230	return 0;
	231	} else {
	232	printk(KERN_WARNING "isdn_x25iface_connect_ind: "
	233	" out of memory -- disconnecting\n");
475be4d8	234	cprot->dops->disconn_req(cprot);
1da177e4 LT	235	return -1;
	236	}
	237	}
475be4d8 JP	238
475be4d8 JP	239	/* a disconnect is indicated by lower layer
1da177e4	240	*/
3e206b0a	241	static int isdn_x25iface_disconn_ind(struct concap_proto *cprot)
1da177e4 LT	242	{
1da177e4 LT	243	struct sk_buff *skb;
475be4d8 JP	244	enum wan_states *state_p
	245	= &(((ix25_pdata_t *)(cprot->proto_data))->state);
	246	IX25DEBUG("isdn_x25iface_disconn_ind %s \n", MY_DEVNAME(cprot->net_dev));
	247	if (*state_p == WAN_UNCONFIGURED) {
	248	printk(KERN_WARNING
1da177e4 LT	249	"isdn_x25iface_disconn_ind while unconfigured\n");
	250	return -1;
	251	}
475be4d8	252	if (!cprot->net_dev) return -1;
1da177e4 LT	253	*state_p = WAN_DISCONNECTED;
1da177e4 LT	254	skb = dev_alloc_skb(1);
475be4d8	255	if (skb) {
4150bbf3	256	*(skb_put(skb, 1)) = X25_IFACE_DISCONNECT;
1da177e4 LT	257	skb->protocol = x25_type_trans(skb, cprot->net_dev);
	258	netif_rx(skb);
	259	return 0;
	260	} else {
	261	printk(KERN_WARNING "isdn_x25iface_disconn_ind:"
	262	" out of memory\n");
	263	return -1;
	264	}
	265	}
	266
	267	/* process a frame handed over to us from linux network layer. First byte
	268	semantics as defined in Documentation/networking/x25-iface.txt
475be4d8	269	*/
3e206b0a	270	static int isdn_x25iface_xmit(struct concap_proto cprot, struct sk_buff skb)
1da177e4 LT	271	{
1da177e4 LT	272	unsigned char firstbyte = skb->data[0];
475be4d8	273	enum wan_states state = &((ix25_pdata_t )cprot->proto_data)->state;
1da177e4	274	int ret = 0;
4150bbf3	275	IX25DEBUG("isdn_x25iface_xmit: %s first=%x state=%d\n",
475be4d8 JP	276	MY_DEVNAME(cprot->net_dev), firstbyte, *state);
475be4d8 JP	277	switch (firstbyte) {
4150bbf3	278	case X25_IFACE_DATA:
475be4d8	279	if (*state == WAN_CONNECTED) {
1da177e4	280	skb_pull(skb, 1);
475be4d8 JP	281	cprot->net_dev->trans_start = jiffies;
475be4d8 JP	282	ret = (cprot->dops->data_req(cprot, skb));
1da177e4	283	/* prepare for future retransmissions */
475be4d8	284	if (ret) skb_push(skb, 1);
1da177e4 LT	285	return ret;
1da177e4 LT	286	}
475be4d8	287	illegal_state_warn(*state, firstbyte);
1da177e4	288	break;
4150bbf3	289	case X25_IFACE_CONNECT:
475be4d8	290	if (*state == WAN_DISCONNECTED) {
1da177e4	291	*state = WAN_CONNECTING;
475be4d8 JP	292	ret = cprot->dops->connect_req(cprot);
475be4d8 JP	293	if (ret) {
1da177e4 LT	294	/* reset state and notify upper layer about
	295	* immidiatly failed attempts */
	296	isdn_x25iface_disconn_ind(cprot);
	297	}
	298	} else {
475be4d8	299	illegal_state_warn(*state, firstbyte);
1da177e4 LT	300	}
1da177e4 LT	301	break;
4150bbf3	302	case X25_IFACE_DISCONNECT:
475be4d8 JP	303	switch (*state) {
475be4d8 JP	304	case WAN_DISCONNECTED:
1da177e4 LT	305	/* Should not happen. However, give upper layer a
	306	chance to recover from inconstistency but don't
	307	trust the lower layer sending the disconn_confirm
	308	when already disconnected */
	309	printk(KERN_WARNING "isdn_x25iface_xmit: disconnect "
475be4d8	310	" requested while disconnected\n");
1da177e4 LT	311	isdn_x25iface_disconn_ind(cprot);
	312	break; /* prevent infinite loops */
	313	case WAN_CONNECTING:
	314	case WAN_CONNECTED:
	315	*state = WAN_DISCONNECTED;
475be4d8	316	cprot->dops->disconn_req(cprot);
1da177e4 LT	317	break;
1da177e4 LT	318	default:
475be4d8	319	illegal_state_warn(*state, firstbyte);
1da177e4 LT	320	}
1da177e4 LT	321	break;
4150bbf3	322	case X25_IFACE_PARAMS:
1da177e4 LT	323	printk(KERN_WARNING "isdn_x25iface_xmit: setting of lapb"
	324	" options not yet supported\n");
	325	break;
	326	default:
	327	printk(KERN_WARNING "isdn_x25iface_xmit: frame with illegal"
	328	" first byte %x ignored:\n", firstbyte);
	329	}
	330	dev_kfree_skb(skb);
	331	return 0;
	332	}