333 lines
9.8 KiB
C
333 lines
9.8 KiB
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_u8(skb, 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_u8(skb, 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);
|
|
netif_trans_update(cprot->net_dev);
|
|
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;
|
|
}
|