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/*
* NET An implementation of the IEEE 802.2 LLC protocol for the
* LINUX operating system. LLC is implemented as a set of
* state machines and callbacks for higher networking layers.
*
* Code for initialization, termination, registration and
* MAC layer glue.
*
* Written by Tim Alpaerts, Tim_Alpaerts@toyota-motor-europe.com
*
* 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.
*
* Changes
* Alan Cox : Chainsawed to Linux format
* Added llc_ to names
* Started restructuring handlers
*
* Horst von Brand : Add #include <linux/string.h>
*/
#include <linux/module.h>
#include <linux/version.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/unistd.h>
#include <linux/string.h>
#include <linux/netdevice.h>
#include <linux/init.h>
#include <net/p8022.h>
#include <asm/byteorder.h>
#include <net/llc_frame.h>
#include <net/llc.h>
/*
* All incoming frames pass thru mac_data_indicate().
* On entry the llc structure related to the frame is passed as parameter.
* The received sk_buffs with pdus other than I_CMD and I_RSP
* are freed by mac_data_indicate() after processing,
* the I pdu buffers are freed by the cl2llc client when it no longer needs
* the skb.
*/
int llc_mac_data_indicate(llcptr lp, struct sk_buff *skb)
{
int ll; /* logical length == 802.3 length field */
unsigned char p_flag;
unsigned char type;
frameptr fr;
int free=1;
lp->inc_skb=NULL;
/*
* Truncate buffer to true 802.3 length
* [FIXME: move to 802.2 demux]
*/
ll = *(skb->data -2) * 256 + *(skb->data -1);
skb_trim( skb, ll );
fr = (frameptr) skb->data;
type = llc_decode_frametype( fr );
if (type <= FRMR_RSP)
{
/*
* PDU is of the type 2 set
*/
if ((lp->llc_mode == MODE_ABM)||(type == SABME_CMD))
llc_process_otype2_frame(lp, skb, type);
}
else
{
/*
* PDU belongs to type 1 set
*/
p_flag = fr->u_hdr.u_pflag;
switch(type)
{
case TEST_CMD:
llc_sendpdu(lp, TEST_RSP, 0,ll -3,
fr->u_hdr.u_info);
break;
case TEST_RSP:
lp->llc_callbacks|=LLC_TEST_INDICATION;
lp->inc_skb=skb;
free=0;
break;
case XID_CMD:
/*
* Basic format XID is handled by LLC itself
* Doc 5.4.1.1.2 p 48/49
*/
if ((ll == 6)&&(fr->u_hdr.u_info[0] == 0x81))
{
lp->k = fr->u_hdr.u_info[2];
llc_sendpdu(lp, XID_RSP,
fr->u_hdr.u_pflag, ll -3,
fr->u_hdr.u_info);
}
break;
case XID_RSP:
if( ll == 6 && fr->u_hdr.u_info[0] == 0x81 )
{
lp->k = fr->u_hdr.u_info[2];
}
lp->llc_callbacks|=LLC_XID_INDICATION;
lp->inc_skb=skb;
free=0;
break;
case UI_CMD:
lp->llc_callbacks|=LLC_UI_DATA;
skb_pull(skb,3);
lp->inc_skb=skb;
free=0;
break;
default:;
/*
* All other type 1 pdus ignored for now
*/
}
}
if (free&&(!(IS_IFRAME(fr))))
{
/*
* No auto free for I pdus
*/
skb->sk = NULL;
kfree_skb(skb);
}
if(lp->llc_callbacks)
{
if ( lp->llc_event != NULL ) lp->llc_event(lp);
lp->llc_callbacks=0;
}
return 0;
}
/*
* Create an LLC client. As it is the job of the caller to clean up
* LLC's on device down, the device list must be locked before this call.
*/
int register_cl2llc_client(llcptr lp, const char *device, void (*event)(llcptr), u8 *rmac, u8 ssap, u8 dsap)
{
char eye_init[] = "LLC\0";
memset(lp, 0, sizeof(*lp));
lp->dev = __dev_get_by_name(device);
if(lp->dev == NULL)
return -ENODEV;
memcpy(lp->eye, eye_init, sizeof(lp->eye));
lp->rw = 1;
lp->k = 127;
lp->n1 = 1490;
lp->n2 = 10;
lp->timer_interval[P_TIMER] = HZ; /* 1 sec */
lp->timer_interval[REJ_TIMER] = HZ/8;
lp->timer_interval[ACK_TIMER] = HZ/8;
lp->timer_interval[BUSY_TIMER] = HZ*2;
lp->local_sap = ssap;
lp->llc_event = event;
memcpy(lp->remote_mac, rmac, sizeof(lp->remote_mac));
lp->state = 0;
lp->llc_mode = MODE_ADM;
lp->remote_sap = dsap;
skb_queue_head_init(&lp->atq);
skb_queue_head_init(&lp->rtq);
MOD_INC_USE_COUNT;
return 0;
}
void unregister_cl2llc_client(llcptr lp)
{
llc_cancel_timers(lp);
MOD_DEC_USE_COUNT;
kfree(lp);
}
EXPORT_SYMBOL(register_cl2llc_client);
EXPORT_SYMBOL(unregister_cl2llc_client);
EXPORT_SYMBOL(llc_data_request);
EXPORT_SYMBOL(llc_unit_data_request);
EXPORT_SYMBOL(llc_test_request);
EXPORT_SYMBOL(llc_xid_request);
EXPORT_SYMBOL(llc_mac_data_indicate);
EXPORT_SYMBOL(llc_cancel_timers);
#define ALL_TYPES_8022 0
static int __init llc_init(void)
{
printk(KERN_NOTICE "IEEE 802.2 LLC for Linux 2.1 (c) 1996 Tim Alpaerts\n");
return 0;
}
module_init(llc_init);
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